Index: trunk/psphot/src/psphotRoughClass.c
===================================================================
--- trunk/psphot/src/psphotRoughClass.c	(revision 21183)
+++ trunk/psphot/src/psphotRoughClass.c	(revision 23989)
@@ -91,5 +91,5 @@
 	return false;
     }
-    if (!psfClump.X || !psfClump.Y) {
+    if (!psfClump.X || !psfClump.Y || isnan(psfClump.X) || isnan(psfClump.Y)) {
 	psLogMsg ("psphot", 4, "Failed to find a valid PSF clump for region %f,%f - %f,%f\n", region->x0, region->y0, region->x1, region->y1);
 	return false;