diff --git a/ChangeLog b/ChangeLog
index d2b898ad4..0dd0c8f8f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2009-09-22: Paolo Nenzi
+ * b4ld.c, b4temp.c: Updated BSIM4 code to BSIM 4.6.5 
+   according to BSIM 4.6.5 bug report. 
+
 2009-09-20 Holger Vogt
  * inpmkmod.c: fix bug no. 2859013
  * INSTALL corrected
diff --git a/src/spicelib/devices/bsim4/b4ld.c b/src/spicelib/devices/bsim4/b4ld.c
index c3963662a..35c14750d 100644
--- a/src/spicelib/devices/bsim4/b4ld.c
+++ b/src/spicelib/devices/bsim4/b4ld.c
@@ -660,7 +660,7 @@ for (; model != NULL; model = model->BSIM4nextModel)
           /* Source/drain junction diode DC model begins */
           Nvtms = model->BSIM4vtm * model->BSIM4SjctEmissionCoeff;
 	  if ((here->BSIM4Aseff <= 0.0) && (here->BSIM4Pseff <= 0.0))
-	  {   SourceSatCurrent = 1.0e-14;
+	  {   SourceSatCurrent = 0.0;
 	  }
           else
           {   SourceSatCurrent = here->BSIM4Aseff * model->BSIM4SjctTempSatCurDensity
@@ -758,7 +758,7 @@ for (; model != NULL; model = model->BSIM4nextModel)
 
           Nvtmd = model->BSIM4vtm * model->BSIM4DjctEmissionCoeff;
 	  if ((here->BSIM4Adeff <= 0.0) && (here->BSIM4Pdeff <= 0.0))
-	  {   DrainSatCurrent = 1.0e-14;
+	  {   DrainSatCurrent = 0.0;
 	  }
           else
           {   DrainSatCurrent = here->BSIM4Adeff * model->BSIM4DjctTempSatCurDensity
diff --git a/src/spicelib/devices/bsim4/b4temp.c b/src/spicelib/devices/bsim4/b4temp.c
index 368ffcdfc..3be470c4c 100644
--- a/src/spicelib/devices/bsim4/b4temp.c
+++ b/src/spicelib/devices/bsim4/b4temp.c
@@ -1729,12 +1729,19 @@ int Size_Not_Found, i;
               DMDGeff = model->BSIM4dmdg - model->BSIM4dmcgt;
 
 	      if (here->BSIM4sourcePerimeterGiven)
+              { if(here->BSIM4sourcePerimeter == 0.0)
+              here->BSIM4Pseff = 0.0;
+              else if (here->BSIM4sourcePerimeter < 0.0)
+              { printf("Warning: Source Perimeter is specified as negative, it is set to zero.\n");
+              here->BSIM4Pseff = 0.0;}
+              else
 	      {   if (model->BSIM4perMod == 0)
 	              here->BSIM4Pseff = here->BSIM4sourcePerimeter;
 		  else
 		      here->BSIM4Pseff = here->BSIM4sourcePerimeter 
 				       - pParam->BSIM4weffCJ * here->BSIM4nf;
 	      }
+              }
 	      else
 	          BSIM4PAeffGeo(here->BSIM4nf, here->BSIM4geoMod, here->BSIM4min, 
                                     pParam->BSIM4weffCJ, DMCGeff, DMCIeff, DMDGeff,
@@ -1745,12 +1752,19 @@ int Size_Not_Found, i;
 			  
 			  
               if (here->BSIM4drainPerimeterGiven)
+              { if(here->BSIM4drainPerimeter = 0.0)
+              here->BSIM4Pdeff = 0.0;
+              else if(here->BSIM4drainPerimeter < 0.0)
+              { printf("Warning: Drain Perimeter is specified as negative, it is set to zero\n");
+              here->BSIM4Pdeff = 0.0;}
+              else
               {   if (model->BSIM4perMod == 0)
                       here->BSIM4Pdeff = here->BSIM4drainPerimeter;
                   else
                       here->BSIM4Pdeff = here->BSIM4drainPerimeter 
 				       - pParam->BSIM4weffCJ * here->BSIM4nf;
               }
+              }
               else
                   BSIM4PAeffGeo(here->BSIM4nf, here->BSIM4geoMod, here->BSIM4min,
                                     pParam->BSIM4weffCJ, DMCGeff, DMCIeff, DMDGeff,
@@ -1840,7 +1854,7 @@ int Size_Not_Found, i;
 
               Nvtms = model->BSIM4vtm * model->BSIM4SjctEmissionCoeff;
               if ((here->BSIM4Aseff <= 0.0) && (here->BSIM4Pseff <= 0.0))
-              {   SourceSatCurrent = 1.0e-14;
+              {   SourceSatCurrent = 0.0;
               }
               else
               {   SourceSatCurrent = here->BSIM4Aseff * model->BSIM4SjctTempSatCurDensity
@@ -1899,7 +1913,7 @@ int Size_Not_Found, i;
 
               Nvtmd = model->BSIM4vtm * model->BSIM4DjctEmissionCoeff;
 	      if ((here->BSIM4Adeff <= 0.0) && (here->BSIM4Pdeff <= 0.0))
-              {   DrainSatCurrent = 1.0e-14;
+              {   DrainSatCurrent = 0.0;
               }
               else
               {   DrainSatCurrent = here->BSIM4Adeff * model->BSIM4DjctTempSatCurDensity