Index: branches/eam_branches/20091201/psModules/src/objects/pmPSF.c
===================================================================
--- branches/eam_branches/20091201/psModules/src/objects/pmPSF.c	(revision 26819)
+++ branches/eam_branches/20091201/psModules/src/objects/pmPSF.c	(revision 26832)
@@ -415,4 +415,8 @@
 
     pmModel *model = pmModelFromPSFforXY(psf, x, y, 1.0); // Model of source
+    if (!model) {
+        psError(PS_ERR_UNKNOWN, false, "Unable to determine PSF model at %f,%f\n", x, y);
+        return NAN;
+    }
     psF32 *params = model->params->data.F32; // Model parameters
     psEllipseAxes axes = pmPSF_ModelToAxes(params, MAX_AXIS_RATIO); // Ellipse axes