diff --git a/src/token.c b/src/token.c
index e309a361..a7090cd8 100644
--- a/src/token.c
+++ b/src/token.c
@@ -1656,7 +1656,7 @@ void print_spice_subckt(FILE *fd, int symbol)
  const char *tclres;
 
  my_strdup(103, &format1, get_tok_value(xctx->sym[symbol].prop_ptr,"format",2));
- dbg(0, "print_spice_subckt(): format1=%s\n", format1);
+ dbg(1, "print_spice_subckt(): format1=%s\n", format1);
  if(strstr(format1, "tcleval(") == format1) {
     tclres = tcl_hook2(&format1);
     if(!strcmp(tclres, "?\n")) my_strdup(1529, &format,  format1 + 8);
@@ -1664,7 +1664,7 @@ void print_spice_subckt(FILE *fd, int symbol)
  } else {
    my_strdup(1530, &format,  format1);
  }
- dbg(0, "print_spice_subckt(): format=%s\n", format);
+ dbg(1, "print_spice_subckt(): format=%s\n", format);
  if( format==NULL ) {
    my_free(1012, &format);
    return; /* no format */
diff --git a/xschem_library/examples/test_backannotated_subckt.sch b/xschem_library/examples/test_backannotated_subckt.sch
index 9ec2e82a..755c390d 100644
--- a/xschem_library/examples/test_backannotated_subckt.sch
+++ b/xschem_library/examples/test_backannotated_subckt.sch
@@ -1,4 +1,4 @@
-v {xschem version=2.9.8 file_version=1.2 }
+v {xschem version=3.1.0 file_version=1.2 }
 G {}
 K {}
 V {}
@@ -12,18 +12,22 @@ attribute to calculate "Res" and "Cap" subcircuit parameters from W and L
 instance parameters.
 Tcl scripts can be loaded in xcshemrc by appending a tcl file name to variable
 tcl_files.} 40 -390 2 1 0.5 0.5 {layer=8 }
-T {proc calc_rc \{ L W \} \{ return "Res=[expr 1200*$L/$W] Cap=[expr 1e-3*$W*$L]"\} } 30 -320 0 0 0.4 0.4 { font=monospace}
+T {proc calc_rc \{ L W \} \{
+ if \{[catch \{expr 1200*$L/$W\} res]\} \{set res -1\}
+ if \{[catch \{expr 1e-3*$W*$L\} cap]\} \{set cap -1\}
+ return "Res=$res Cap=$cap"
+\} } 270 -370 0 0 0.4 0.4 { font=monospace}
 T {Dynamic calculation of subcircuit parameters} 80 -730 0 0 0.8 0.8 {}
 N 140 -130 140 -100 { lab=0}
 N 140 -210 160 -210 { lab=IN}
 N 140 -210 140 -190 { lab=IN}
-C {lab_pin.sym} 620 -190 0 1 {name=p1 lab=OUT}
-C {lab_pin.sym} 320 -190 0 0 {name=p2 lab=IN}
+C {lab_pin.sym} 670 -150 0 1 {name=p1 lab=OUT}
+C {lab_pin.sym} 370 -150 0 0 {name=p2 lab=IN}
 C {title.sym} 160 -30 0 0 {name=l1 author="Stefan Schippers"}
 C {vsource.sym} 140 -160 0 0 {name=V1 value="pwl 0 0 10n 0 11n 5"}
 C {lab_pin.sym} 140 -100 0 0 {name=l2 sig_type=std_logic lab=0}
 C {lab_pin.sym} 160 -210 0 1 {name=p3 lab=IN}
-C {rcline.sym} 470 -190 0 0 {name=x1 L=1e-4 W=0.5e-6
+C {rcline.sym} 520 -150 0 0 {name=x1 L=1e-4 W=0.5e-6
 }
 C {code_shown.sym} 890 -190 0 0 {name=STIMULI
 only_toplevel=false