Index: trunk/psphot/src/psModulesUtils.c
===================================================================
--- trunk/psphot/src/psModulesUtils.c	(revision 5772)
+++ trunk/psphot/src/psModulesUtils.c	(revision 5802)
@@ -65,6 +65,12 @@
     float sky = model->params->data.F32[0];
 
+    *fitMag = 99.0;
+    *obsMag = 99.0;
+
     pmModelFlux modelFluxFunc = pmModelFlux_GetFunction (model->type);
     fitSum = modelFluxFunc (model->params);
+    if (fitSum <= 0) return false;
+    if (!isfinite(fitSum)) return false;
+    *fitMag = -2.5*log10(fitSum);
 
     for (int ix = 0; ix < image->numCols; ix++) {
@@ -75,8 +81,6 @@
     }
     if (obsSum <= 0) return false;
-    if (fitSum <= 0) return false;
+    *obsMag = -2.5*log10(obsSum);
 
-    *fitMag = -2.5*log10(fitSum);
-    *obsMag = -2.5*log10(obsSum);
     return (true);
 }