Index: trunk/Ohana/src/opihi/cmd.data/vgauss.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/vgauss.c	(revision 10071)
+++ trunk/Ohana/src/opihi/cmd.data/vgauss.c	(revision 10307)
@@ -53,5 +53,7 @@
   v1 = svec[0].elements;
   v2 = dy;
-  for (i = 0; i < Npts; i++, v1++, v2++) *v2 = 1.0 / (*v1 * *v1);
+  for (i = 0; i < Npts; i++, v1++, v2++) {
+      *v2 = (*v1 == 0.0) ? 0.0 : 1.0 / (*v1 * *v1);
+  } 
   
   ochisq = mrqinit (xvec[0].elements, yvec[0].elements, dy, Npts, par, Npar, fgaussOD, !Quiet);