diff --git a/VERSION b/VERSION
index 12f037c..adc464c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5.228
+1.5.229
diff --git a/base/flatten.c b/base/flatten.c
index 7c3b6a4..ad6516e 100644
--- a/base/flatten.c
+++ b/base/flatten.c
@@ -66,7 +66,7 @@ void flattenCell(char *name, int file)
   else
      ThisCell = LookupCellFile(name, file);
   if (ThisCell == NULL) {
-    Printf("No cell %s found.\n", name);
+    Printf("No cell %s (%d) found.\n", name, file);
     return;
   }
 
@@ -282,13 +282,14 @@ int flattenInstancesOf(char *name, int fnum, char *instance)
   }
   else {
     if (Debug) 
-       Printf("Flattening instances of %s within cell: %s\n", instance, name);
+       Printf("Flattening instances of %s within cell: %s (%d)\n", instance,
+			name, fnum);
     if (fnum == -1)
        ThisCell = LookupCell(name);
     else
        ThisCell = LookupCellFile(name, fnum);
     if (ThisCell == NULL) {
-      Printf("No cell %s found.\n", name);
+      Printf("No cell %s (%d) found.\n", name, fnum);
       return 0;
     }
   }
@@ -688,7 +689,7 @@ void convertGlobalsOf(char *name, int fnum, char *instance)
       else
          ThisCell = LookupCellFile(name, fnum);
       if (ThisCell == NULL) {
-	 Printf("No cell %s found.\n", name);
+	 Printf("No cell %s (%d) found.\n", name, fnum);
 	 return;
       }
    }
@@ -1118,7 +1119,7 @@ int UniquePins(char *name, int filenum)
       ThisCell = LookupCellFile(name, filenum);
 
    if (ThisCell == NULL) {
-      Printf("No cell %s found.\n", name);
+      Printf("No cell %s (%d) found.\n", name, filenum);
       return 0;
    }
 
@@ -1159,7 +1160,8 @@ int UniquePins(char *name, int filenum)
 	       continue;
 	    }
 	    else {
-	       Printf("Duplicate pin %s in cell %s\n", ob->name, ThisCell->name);
+	       Printf("Duplicate pin %s in cell %s (%d)\n", ob->name,
+				ThisCell->name, filenum);
 	    }
 	 }
 	 if (nodecount[ob->node] > 1) {
@@ -1360,7 +1362,7 @@ int CleanupPins(char *name, int filenum)
       ThisCell = LookupCellFile(name, filenum);
 
    if (ThisCell == NULL) {
-      Printf("No cell %s found.\n", name);
+      Printf("No cell %s (%d) found.\n", name, filenum);
       return 0;
    }
 
diff --git a/base/netcmp.c b/base/netcmp.c
index b3fb4a0..fa2ae92 100644
--- a/base/netcmp.c
+++ b/base/netcmp.c
@@ -6185,7 +6185,8 @@ void PrintPropertyResults(int do_list)
 
 /*----------------------------------------------------------------------*/
 /* Return 0 if perfect matching found, else return number of		*/
-/* automorphisms, and return -1 if invalid matching found. 		*/
+/* automorphisms, and return -1 if invalid matching found, 		*/
+/* and return -2 if there is a port count mismatch.			*/
 /*----------------------------------------------------------------------*/
 
 int VerifyMatching(void)
@@ -6196,6 +6197,9 @@ int VerifyMatching(void)
   struct Element *E;
   struct Node *N;
   int C1, C2, result;
+  int P1, P2;
+  struct objlist *ob1, *ob2;
+  int portMismatch = 0;
 
   if (BadMatchDetected) return(-1);
   
@@ -6216,14 +6220,40 @@ int VerifyMatching(void)
     }
   }
 
+  P1 = P2 = 0;
   for (NC = NodeClasses; NC != NULL; NC = NC->next) {
     C1 = C2 = 0;
     for (N = NC->nodes; N != NULL; N = N->next) {
       (N->graph == Circuit1->file) ? C1++ : C2++;
+      if (IsPort(N->object)) (N->graph == Circuit1->file) ? P1++ : P2++;
     }
     if (C1 != C2) return(-1);
+    if (P1 != P2) portMismatch = 1;
     if (C1 != 1) ret++;
   }
+
+  P1 = P2 = 0;
+  if (ret == 0) {	/* automorphisms have precedence over port count mismatch */
+     if (portMismatch) return -2;
+
+     /* Count ports in each subcircuit including disconnected ports */
+     for (ob1 = Circuit1->cell; ob1 && IsPort(ob1); ob1 = ob1->next, P1++);
+     for (ob2 = Circuit2->cell; ob2 && IsPort(ob2); ob2 = ob2->next, P2++);
+     if (P1 == P2) {	// pin counts match.  Make sure disconnected pins match, too.
+	for (ob1 = Circuit1->cell; ob1 && IsPort(ob1); ob1 = ob1->next) {
+	   if (ob1->node == -1) {	// disconnected pin
+	      for (ob2 = Circuit2->cell; ob2 && IsPort(ob2); ob2 = ob2->next) {
+		 if (ob2->node == -1 && (*matchfunc)(ob1->name, ob2->name))
+		     break;	// disconnected pin match 
+	      }
+	      if (ob2 == NULL) return -2;
+	   }
+	}
+     }
+     else {	// pin count mismatch
+	return -2;
+     }
+  }
   return(ret);
 }
 
@@ -6322,7 +6352,7 @@ int ResolveAutomorphsByPin()
     FractureElementClass(&ElementClasses); 
     FractureNodeClass(&NodeClasses); 
     ExhaustiveSubdivision = 1;
-    while (!Iterate() && VerifyMatching() != -1); 
+    while (!Iterate() && VerifyMatching() >= 0); 
     return(VerifyMatching());
 }
 
@@ -6425,7 +6455,7 @@ int ResolveAutomorphsByProperty()
     FractureElementClass(&ElementClasses); 
     FractureNodeClass(&NodeClasses); 
     ExhaustiveSubdivision = 1;
-    while (!Iterate() && VerifyMatching() != -1); 
+    while (!Iterate() && VerifyMatching() >= 0); 
     return(VerifyMatching());
 }
 
@@ -6502,7 +6532,7 @@ int ResolveAutomorphisms()
   FractureElementClass(&ElementClasses);
   FractureNodeClass(&NodeClasses);
   ExhaustiveSubdivision = 1;
-  while (!Iterate() && VerifyMatching() != -1);
+  while (!Iterate() && VerifyMatching() >= 0);
   return(VerifyMatching());
 }
 
@@ -7197,32 +7227,31 @@ struct nlist *addproxies(struct hashlist *p, void *clientdata)
     return NULL;	/* Keep the search going */
 }
 
-/*------------------------------------------------------*/
-/* Declare that the device class "name1" is equivalent	*/
-/* to class "name2".  This is the same as the above	*/
-/* routine, except that the cells must be at the top	*/
-/* of the compare queue, and must already be proven	*/
-/* equivalent by LVS.  Determine a pin correspondence,	*/
-/* then modify all instances of "name2" to match all	*/
-/* instances of "name1" by pin reordering.  If either	*/
-/* cell has disconnected pins, they are shuffled to the	*/
-/* end of the pin list.  If two or more pins correspond	*/
-/* to net automorphisms, then they are added to the	*/
-/* list of permuted pins.				*/
-/*							*/
-/* NOTE:  This routine must not be called on any	*/
-/* circuit pair that has not been matched.  If a 	*/
-/* circuit pair has been matched with automorphisms,	*/
-/* then some pins may be matched arbitrarily.		*/
-/*							*/
-/* If "dolist" is 1, append the list representing the	*/
-/* output (if any) to variable tcl_out, if it exists.	*/
-/*							*/
-/* Return codes:					*/
-/* 2: Neither cell had pins, so matching is unnecessary	*/
-/* 1: Exact match					*/
-/* 0: Inexact match resolved by proxy pin insertion	*/
-/*------------------------------------------------------*/
+/*--------------------------------------------------------------*/
+/* Declare that the device class "name1" is equivalent to class	*/
+/* "name2".  This is the same as the above routine, except that	*/
+/* the cells must be at the top	of the compare queue, and must	*/
+/* already be proven equivalent by LVS.  Determine a pin	*/
+/* correspondence, then modify all instances of "name2" to	*/
+/* match all instances of "name1" by pin reordering.  If either	*/
+/* cell has disconnected pins, they are shuffled to the	end of	*/
+/* the pin list.  If two or more pins correspond to net		*/
+/* automorphisms, then they are added to the list of permuted	*/
+/* pins.							*/
+/*								*/
+/* NOTE:  This routine must not be called on any circuit pair	*/
+/* that has not been matched.  If a circuit pair has been	*/
+/* matched with automorphisms, then some pins may be matched	*/
+/* arbitrarily.							*/
+/*								*/
+/* If "dolist" is 1, append the list representing the output	*/
+/* (if any) to variable tcl_out, if it exists.			*/
+/*								*/
+/* Return codes:						*/
+/*  2: Neither cell had pins, so matching is unnecessary	*/
+/*  1: Exact match						*/
+/*  0: Inexact match resolved by proxy pin insertion.		*/
+/*--------------------------------------------------------------*/
 
 int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
 {
@@ -7817,7 +7846,7 @@ int MatchPins(struct nlist *tc1, struct nlist *tc2, int dolist)
    }
 
    /* Check for ports that did not get ordered */
-   for (obn = tc2->cell; obn && (obn->type == PORT); obn = obn->next) {
+   for (obn = tc2->cell; obn && IsPort(obn); obn = obn->next) {
       if (obn->model.port == -1) {
 	 if (obn->node == -1) {
 	    // This only happens when pins have become separated from any net.
@@ -7995,10 +8024,12 @@ int EquivalentElement(char *name, struct nlist *circuit, struct objlist **retobj
 void FlattenCurrent()
 {
    if (Circuit1 != NULL && Circuit2 != NULL) {
-      Fprintf(stdout, "Flattening subcell %s\n", Circuit1->name);
+      Fprintf(stdout, "Flattening subcell %s (%d)\n", Circuit1->name,
+		Circuit1->file);
       FlattenInstancesOf(Circuit1->name, Circuit1->file);
 
-      Fprintf(stdout, "Flattening subcell %s\n", Circuit2->name);
+      Fprintf(stdout, "Flattening subcell %s (%d)\n", Circuit2->name,
+		Circuit2->file);
       FlattenInstancesOf(Circuit2->name, Circuit2->file);
    }
 }
@@ -8069,7 +8100,25 @@ int Compare(char *cell1, char *cell2)
     PrintIllegalClasses();
     return(0);
   }
-  if (automorphisms == 0) Fprintf(stdout, "Circuits match correctly.\n");
+
+  if (automorphisms > 0) {
+     Fprintf(stdout, "Circuits match with %d symmetries.\n", automorphisms);
+     if (VerboseOutput) PrintAutomorphisms();
+
+     /* arbitrarily resolve automorphisms */
+     Fprintf(stdout, "\n");
+     Fprintf(stdout, "Resolving automorphisms by arbitrary symmetry breaking:\n");
+     while ((automorphisms = ResolveAutomorphisms()) > 0) ;
+     if (automorphisms == -1) {
+	MatchFail(cell1, cell2);
+	Fprintf(stdout, "Circuits do not match.\n");
+	return 0;
+     }
+  }
+  if (automorphisms == -2) {	// Port count mismatch
+     Fprintf(stderr, "Port counts do not match.\n");
+     return 0;
+  }
   if (PropertyErrorDetected == 1) {
      Fprintf(stdout, "There were property errors.\n");
      PrintPropertyResults(0);
@@ -8078,22 +8127,10 @@ int Compare(char *cell1, char *cell2)
      Fprintf(stdout, "There were missing properties.\n");
      PrintPropertyResults(0);
   }
-  if (automorphisms == 0) return(1);
+  else
+     Fprintf(stdout, "Circuits match correctly.\n");
 
-  Fprintf(stdout, "Circuits match with %d automorphisms.\n", automorphisms);
-  if (VerboseOutput) PrintAutomorphisms();
-
-  /* arbitrarily resolve automorphisms */
-  Fprintf(stdout, "\n");
-  Fprintf(stdout, "Resolving automorphisms by arbitrary symmetry breaking:\n");
-  while ((automorphisms = ResolveAutomorphisms()) > 0) ;
-  if (automorphisms == -1) {
-    MatchFail(cell1, cell2);
-    Fprintf(stdout, "Circuits do not match.\n");
-    return(0);
-  }
-  Fprintf(stdout, "Circuits match correctly.\n");
-  return(1);
+  return 1;
 }
 
 
@@ -8147,9 +8184,12 @@ void NETCOMP(void)
 	  PrintIllegalClasses();
 	  Fprintf(stdout, "Netlists do not match.\n");
 	}
+	else if (automorphisms == -2) {		// port count mismatch
+	   Fprintf(stdout, "Port counts do not match.\n");
+	}
 	else {
 	  if (automorphisms) 
-	    Printf("Circuits match with %d automorphisms.\n", automorphisms);
+	    Printf("Circuits match with %d symmetries.\n", automorphisms);
 	  else Printf("Circuits match correctly.\n");
 	}
       }
@@ -8162,11 +8202,13 @@ void NETCOMP(void)
 	while (!Iterate()) ; 
 	automorphisms = VerifyMatching();
 	if (automorphisms == -1) Fprintf(stdout, "Netlists do not match.\n");
+	else if (automorphisms == -2) Fprintf(stdout, "Port counts do not match.\n");
 	else {
-	  Printf("Netlists match with %d automorphisms.\n", automorphisms);
+	  Printf("Netlists match with %d symmetries.\n", automorphisms);
 	  while ((automorphisms = ResolveAutomorphisms()) > 0)
 	    Printf("  automorphisms = %d.\n", automorphisms);
 	  if (automorphisms == -1) Fprintf(stdout, "Netlists do not match.\n");
+	  else if (automorphisms == -2) Fprintf(stdout, "Port counts do not match.\n");
 	  else Printf("Circuits match correctly.\n");
 	}
       }
diff --git a/tcltk/netgen.tcl.in b/tcltk/netgen.tcl.in
index f9c1ae8..55f1f10 100644
--- a/tcltk/netgen.tcl.in
+++ b/tcltk/netgen.tcl.in
@@ -532,14 +532,24 @@ proc netgen::lvs { name1 name2 {setupfile setup.tcl} {logfile comp.out} args} {
    }
    set properr {}
    set matcherr {}
-   set pinsgood -1
+   set childMismatch 0		;# 1 indicates black-box child subcircuit mismatch
    while {$endval != {}} {
       if {$dolist == 1} {
          netgen::run -list converge
       } else {
          netgen::run converge
       }
-      netgen::log echo on
+      set pinMismatch 0		;# indicates pin mismatch in top cell
+      set doCheckFlatten 0
+      set doFlatten 0
+      if {[netgen::print queue] == {}} {
+	 set doEquatePins 1 	;# run equate pins on top cell
+      } else {
+	 set doEquatePins 0	;# don't run equate pins unless unique match
+      }
+      set forceMatch 0		;# for pin matching
+      netgen::log echo off
+
       if {[verify equivalent]} {
 	 # Resolve automorphisms by pin and property
 	 if {$dolist == 1} {
@@ -548,98 +558,105 @@ proc netgen::lvs { name1 name2 {setupfile setup.tcl} {logfile comp.out} args} {
             netgen::run resolve
 	 }
 	 set uresult [verify unique]
+	 # uresult:  -3 : unique with property error
+	 #	     -2 : equivalent with port errors
+	 #	     -1 : black box
+	 #	      0 : equivalent but not unique
+	 #	      1 : unique
          if {$uresult == 0} {
+	    netgen::log echo on
 	    netgen::log put "   Networks match locally but not globally.\n"
 	    netgen::log put "   Probably connections are swapped.\n"
 	    netgen::log put "   Check the end of logfile ${logfile} for implicated nodes.\n"
+	    netgen::log echo off
 	    if {$dolist == 1} {
 	       verify -list nodes
 	    } else {
 	       verify nodes
 	    }
-
-	    # Flatten the non-matching subcircuit (but not the top-level cells)
-            if {[netgen::print queue] != {}} {
-	       if {([lsearch $noflat [lindex $endval 0]] == -1) &&
-			([lsearch $noflat [lindex $endval 1]] == -1)} {
-	           netgen::log put "  Flattening non-matched subcircuits $endval\n"
-	           netgen::flatten class "[lindex $endval 0] $fnum1"
-	           netgen::flatten class "[lindex $endval 1] $fnum2"
-	       } else {
-	           netgen::log put "  Continuing with black-boxed subcircuits $endval\n"
-		   lappend matcherr [lindex $endval 0]"($fnum1)"
-		   lappend matcherr [lindex $endval 1]"($fnum2)"
-		   netgen::flatten prohibit "[lindex $endval 0] $fnum1"
-		   netgen::flatten prohibit "[lindex $endval 1] $fnum2"
-	           # Match pins
-                   netgen::log echo off
-	           if {$dolist == 1} {
-		       set result [equate -list -force pins "$fnum1 [lindex $endval 0]" \
-				"$fnum2 [lindex $endval 1]"]
-	           } else {
-		       set result [equate -force pins "$fnum1 [lindex $endval 0]" \
-				"$fnum2 [lindex $endval 1]"]
-	           }
-	           if {$result != 0} {
-		       equate classes "$fnum1 [lindex $endval 0]" \
-			        "$fnum2 [lindex $endval 1]"
-	           }
-	           set pinsgood $result
-                   netgen::log echo on
-	       }
-	    }
+	    set doCheckFlatten 1
 	 } else {
-            netgen::log echo off
-	    if {$dolist == 1} {
-		set result [equate -list pins "$fnum1 [lindex $endval 0]" \
-				"$fnum2 [lindex $endval 1]"]
-	    } else {
-		set result [equate pins "$fnum1 [lindex $endval 0]" \
-				"$fnum2 [lindex $endval 1]"]
-	    }
-	    if {$result != 0} {
-		equate classes "$fnum1 [lindex $endval 0]" \
-			 "$fnum2 [lindex $endval 1]"
-	    }
-	    # If $uresult == -1 then these are black-box entries and
-	    # $pinsgood should not be set to the resulting value.
-	    if {$uresult > 0} {
-	        set pinsgood $result
-	    }
-            netgen::log echo on
+	    # Equate pins for black boxes, unique matches (possibly with property
+	    # errors), and unique with port errors
+	    set doEquatePins 1
+	 }
+	 if {$uresult == -1} {		;# black box
+	    set forceMatch 1
+	 } elseif {$uresult == -3} {	;# property error
+	    lappend properr [lindex $endval 0]
+	 } elseif {$uresult == -2} {	;# unmatched pins
+	    set doCheckFlatten 1
 	 }
-	 if {$uresult == 2} {lappend properr [lindex $endval 0]}
       } else {
-	 # Flatten the non-matching subcircuit (but not the top-level cells)
-         if {[netgen::print queue] != {}} {
+	 # not equivalent
+	 netgen::log echo on
+	 # netgen::log put "  DEBUG: not equivalent $endval\n"
+	 netgen::log echo off
+	 set doCheckFlatten 1
+      }
+      if {$doCheckFlatten} {
+	 # Flatten the non-matching subcircuit (but not the top-level cell,
+	 # or cells explicitly prohibited from flattening)
+	 if {[netgen::print queue] != {}} {
 	    if {([lsearch $noflat [lindex $endval 0]] == -1) &&
-		    ([lsearch $noflat [lindex $endval 1]] == -1)} {
-	       netgen::log put "  Flattening non-matched subcircuits $endval\n"
-	       netgen::flatten class "[lindex $endval 0] $fnum1"
-	       netgen::flatten class "[lindex $endval 1] $fnum2"
-	    } else {
+			([lsearch $noflat [lindex $endval 1]] == -1)} {
+	       set doFlatten 1
+	    } else {	
+	       netgen::log echo on
 	       netgen::log put "  Continuing with black-boxed subcircuits $endval\n"
+	       netgen::log echo off
 	       lappend matcherr [lindex $endval 0]"($fnum1)"
-	       lappend matcherr [lindex $endval 0]"($fnum2)"
-	       # Match pins
-               netgen::log echo off
-	       if {$dolist == 1} {
-		   set result [equate -list -force pins "$fnum1 [lindex $endval 0]" \
-			    "$fnum2 [lindex $endval 1]"]
-	       } else {
-		   set result [equate -force pins "$fnum1 [lindex $endval 0]" \
-			    "$fnum2 [lindex $endval 1]"]
-	       }
-	       if {$result != 0} {
-		   equate classes "$fnum1 [lindex $endval 0]" \
-			    "$fnum2 [lindex $endval 1]"
-	       }
-	       set pinsgood $result
-               netgen::log echo on
+	       lappend matcherr [lindex $endval 1]"($fnum2)"
+	       netgen::flatten prohibit "[lindex $endval 0] $fnum1"
+	       netgen::flatten prohibit "[lindex $endval 1] $fnum2"
+	       set doEquatePins 1
+	       set childMismatch 1
+	       set forceMatch 1
 	    }
 	 }
       }
-      netgen::log echo off
+      if {$doEquatePins} {
+	 # Match pins
+	 if {$dolist == 1} {
+	    if {$forceMatch} {
+	       set result [equate -list -force pins "$fnum1 [lindex $endval 0]" \
+				"$fnum2 [lindex $endval 1]"]
+	    } else {
+	       set result [equate -list pins "$fnum1 [lindex $endval 0]" \
+				"$fnum2 [lindex $endval 1]"]
+	    }
+	 } else {
+	    if {$forceMatch} {
+	       set result [equate -force pins "$fnum1 [lindex $endval 0]" \
+				"$fnum2 [lindex $endval 1]"]
+	    } else {
+	       set result [equate pins "$fnum1 [lindex $endval 0]" \
+				"$fnum2 [lindex $endval 1]"]
+	    }
+	 }
+	 if {$result >= 0} {
+	    equate classes "$fnum1 [lindex $endval 0]" \
+		        "$fnum2 [lindex $endval 1]"
+	 }
+	 # Do not set pinMismatch for black boxes
+	 if {$result < 0} {
+	    if {$result == -1 && [netgen::print queue] != {} && $forceMatch != 1} {
+               # flatten pin mismatch, but not empty cells (-2) or top cell or
+	       # cells prohibited from flattening.
+	       set doFlatten 1
+	    }
+	 } elseif {[netgen::print queue] == {} && $result == 0} {
+	    set pinMismatch 1
+	 }
+      }
+      if {$doFlatten} {
+	 netgen::log echo on
+	 netgen::log put "  Flattening non-matched subcircuits $endval\n"
+	 netgen::log echo off
+	 netgen::flatten class "[lindex $endval 0] $fnum1"
+	 netgen::flatten class "[lindex $endval 1] $fnum2"
+      }
+
       if {$dolist == 1} {
          catch {lappend lvs_final $lvs_out}
          set lvs_out {}
@@ -648,20 +665,23 @@ proc netgen::lvs { name1 name2 {setupfile setup.tcl} {logfile comp.out} args} {
          set endval [netgen::compare hierarchical]
       }
    }
-   netgen::log echo off
-   puts stdout "Result: " nonewline
    netgen::log echo on
-   if {$pinsgood == 0} {
-      # NOTE:  Need to disambiguate these two cases. . .
-      netgen::log put "Cells failed matching, or top level cell failed pin matching.\n"
+   netgen::log put "\nFinal result: "
+   if {$pinMismatch || $childMismatch} {
+      if {$childMismatch} {
+	 netgen::log put "Subcell(s) failed matching.\n"
+      }
+      if {$pinMismatch} {
+	 netgen::log put "Top level cell failed pin matching.\n"
+      }
    } else {
       verify only
    }
    if {$properr != {}} {
-      netgen::log put "The following cells had property errors:\n " [regsub -all { } $properr "\n "] "\n"
+      netgen::log put "\nThe following cells had property errors:\n " [regsub -all { } $properr "\n "] "\n"
    }
    if {$matcherr != {}} {
-      netgen::log put "The following subcells failed to match:\n " [regsub -all { } $matcherr "\n "] "\n"
+      netgen::log put "\nThe following subcells failed to match:\n " [regsub -all { } $matcherr "\n "] "\n"
    }
    if {$dolog} {
       netgen::log end
diff --git a/tcltk/tclnetgen.c b/tcltk/tclnetgen.c
index 7a597ed..165dba2 100644
--- a/tcltk/tclnetgen.c
+++ b/tcltk/tclnetgen.c
@@ -1937,9 +1937,17 @@ _netgen_log(ClientData clientData,
    switch(index) {
       case START_IDX:
 	 LoggingFile = fopen(LogFileName, "w");
+	 if (!LoggingFile) {
+	    Tcl_SetResult(interp, "Could not open log file.", NULL);
+	    return TCL_ERROR;
+	 }
 	 break;
       case RESUME_IDX:
 	 LoggingFile = fopen(LogFileName, "a");
+	 if (!LoggingFile) {
+	    Tcl_SetResult(interp, "Could not open log file.", NULL);
+	    return TCL_ERROR;
+	 }
 	 break;
       case END_IDX:
 	 fclose(LoggingFile);
@@ -1948,6 +1956,10 @@ _netgen_log(ClientData clientData,
       case RESET_IDX:
 	 fclose(LoggingFile);
 	 LoggingFile = fopen(LogFileName, "w");
+	 if (!LoggingFile) {
+	    Tcl_SetResult(interp, "Could not open log file.", NULL);
+	    return TCL_ERROR;
+	 }
 	 break;
       case SUSPEND_IDX:
 	 fclose(LoggingFile);
@@ -2209,11 +2221,11 @@ _netcmp_compare(ClientData clientData,
    hascontents2 = HasContents(tp2);
 
    if (hascontents1 && !hascontents2 && (tp2->flags & CELL_PLACEHOLDER)) {
-       Fprintf(stdout, "Circuit 2 cell %s is a black box; will not flatten "
+       Fprintf(stdout, "\nCircuit 2 cell %s is a black box; will not flatten "
                         "Circuit 1\n", name2);
    }
    else if (hascontents2 && !hascontents1 && (tp1->flags & CELL_PLACEHOLDER)) {
-       Fprintf(stdout, "Circuit 1 cell %s is a black box; will not flatten "
+       Fprintf(stdout, "\nCircuit 1 cell %s is a black box; will not flatten "
                         "Circuit 2\n", name1);
    }
    else if (hascontents1 || hascontents2) {
@@ -2229,6 +2241,10 @@ _netcmp_compare(ClientData clientData,
           DescribeContents(name1, fnum1, name2, fnum2);
        }
    }
+   else {	/* Two empty subcircuits */
+       Fprintf(stdout, "\nCircuit 1 cell %s and Circuit 2 cell %s are black"
+			" boxes.\n", name1, name2);
+   }
    CreateTwoLists(name1, fnum1, name2, fnum2, dolist);
 
    // Return the names of the two cells being compared, if doing "compare
@@ -2485,39 +2501,37 @@ _netcmp_run(ClientData clientData,
 	    ExhaustiveSubdivision = 1;
 	    while (!Iterate() && !InterruptPending);
 	    automorphisms = VerifyMatching();
-	    if (automorphisms == -1)
-	       Fprintf(stdout, "Netlists do not match.\n");
-	    else if (automorphisms == 0)
-	       Fprintf(stdout, "Netlists match uniquely.\n");
-	    else {
+	    if (automorphisms > 0) {
 	       // First try to resolve automorphisms uniquely using
 	       // property matching
 	       automorphisms = ResolveAutomorphsByProperty();
-	       if (automorphisms == 0)
-	          Fprintf(stdout, "Netlists match uniquely.\n");
-	       else if (automorphisms > 0) {
+	       if (automorphisms > 0) {
 	          // Next, attempt to resolve automorphisms uniquely by
 	          // using the pin names
 		  automorphisms = ResolveAutomorphsByPin();
 	       }
-
-	       if (automorphisms == 0)
-	          Fprintf(stdout, "Netlists match uniquely.\n");
-	       else if (automorphisms > 0) {
+	       if (automorphisms > 0) {
 	          // Anything left is truly indistinguishable
-	          Fprintf(stdout, "Netlists match with %d symmetr%s.\n",
-				automorphisms, (automorphisms == 1) ? "y" : "ies");
-
-		  while ((automorphisms = ResolveAutomorphisms()) > 0);
+		  while (ResolveAutomorphisms() > 0);
 	       }
-	       if (automorphisms == -1)
-		  Fprintf(stdout, "Netlists do not match.\n");
-	       else
-		  Fprintf(stdout, "Circuits match correctly.\n");
 	    }
-	    if (PropertyErrorDetected) {
-	       Fprintf(stdout, "There were property errors.\n");
-	       PrintPropertyResults(dolist);
+
+	    if (automorphisms == -1)
+	       Fprintf(stdout, "Netlists do not match.\n");
+	    else if (automorphisms == -2)
+	       Fprintf(stdout, "Netlists match uniquely with port errors.\n");
+	    else {
+	       if (automorphisms == 0)
+	          Fprintf(stdout, "Netlists match uniquely");
+	       else
+	          Fprintf(stdout, "Netlists match with %d symmetr%s",
+				automorphisms, (automorphisms == 1) ? "y" : "ies");
+	       if (PropertyErrorDetected) {
+	          Fprintf(stdout, " with property errors.\n");
+	          PrintPropertyResults(dolist);
+	       }
+	       else
+		  Fprintf(stdout, ".\n");
 	    }
 	    disable_interrupt();
          }
@@ -2535,8 +2549,14 @@ _netcmp_run(ClientData clientData,
 /*		 all, or no option.			*/
 /* Formerly: v						*/
 /* Results:						*/
-/*	For only, equivalent, unique:  Return 1 if 	*/
-/*	verified, zero if not.				*/
+/*	For only, equivalent, unique:  Return 		*/
+/*	 1: verified					*/
+/*	 0: not verified				*/
+/*	-1: no elements or nodes			*/
+/*	-3: verified with property error		*/
+/*   equiv option					*/
+/*	-2: pin mismatch				*/
+/*							*/
 /* Side Effects:					*/
 /*	For options elements, nodes, and all without	*/
 /*	option -list:  Write output to log file.	*/
@@ -2636,7 +2656,7 @@ _netcmp_verify(ClientData clientData,
 	        Tcl_SetObjResult(interp, Tcl_NewIntObj((int)automorphisms));
 	    else if (index == UNIQUE_IDX)
 	        Tcl_SetObjResult(interp, Tcl_NewBooleanObj(0));
-	    else
+	    else if (index > 0)
 	        Printf("Circuits match with %d symmetr%s.\n",
 			automorphisms, (automorphisms == 1) ? "y" : "ies");
 	 }
@@ -2645,11 +2665,13 @@ _netcmp_verify(ClientData clientData,
 		if (PropertyErrorDetected == 0)
 	           Tcl_SetObjResult(interp, Tcl_NewBooleanObj(1));
 	        else
-	           Tcl_SetObjResult(interp, Tcl_NewIntObj(2));
+	           Tcl_SetObjResult(interp, Tcl_NewIntObj(-3));
 	    }
-	    else {
+	    else if (index > 0) {
 	        Fprintf(stdout, "Circuits match uniquely.\n");
-		if (PropertyErrorDetected != 0)
+		if (PropertyErrorDetected == 0)
+		   Fprintf(stdout, ".\n");
+		else
 		   Fprintf(stdout, "Property errors were found.\n");
 	    }
 	 }
@@ -3072,7 +3094,11 @@ _netcmp_equate(ClientData clientData,
 		tp1->flags |= CELL_PLACEHOLDER;
 		tp2->flags |= CELL_PLACEHOLDER;
 	    }
-	    else {
+	    else if (doforce != TRUE) {
+		/* When doforce is TRUE, ElementClass has been set to NULL
+		 * even though circuits contain elements, so this message
+		 * is not correct.
+		 */
 		Fprintf(stdout, "Equate pins:  cell %s and/or %s "
 			"has no elements.\n", name1, name2);
 		/* This is not necessarily an error, so go ahead and match pins. */
@@ -3104,6 +3130,13 @@ _netcmp_equate(ClientData clientData,
 	 else if (result > 0) {
 	    Fprintf(stdout, "Cell pin lists are equivalent.\n");
 	 }
+	 else if (result == -1) {
+	    Fprintf(stdout, "Cell pin lists for %s and %s do not match.\n",
+			name1, name2);
+	 }
+	 else if (result == -2) {
+	    Fprintf(stdout, "Attempt to match empty cell to non-empty cell.\n");
+	 }
 	 else {
 	    Fprintf(stdout, "Cell pin lists for %s and %s altered to match.\n",
 			name1, name2);