Index: trunk/psphot/src/psphotSourceFits.c
===================================================================
--- trunk/psphot/src/psphotSourceFits.c	(revision 36375)
+++ trunk/psphot/src/psphotSourceFits.c	(revision 36863)
@@ -700,5 +700,5 @@
 	model->params->data.F32[PM_PAR_7] = 0.5/indexGuess[i];
 
-	if (!model->modelGuess(model, source, maskVal, markVal)) {
+	if (!model->class->modelGuess(model, source, maskVal, markVal)) {
 	    model->flags |= PM_MODEL_STATUS_BADARGS;
 	    return false;
@@ -723,5 +723,5 @@
     model->flags = PM_MODEL_STATUS_NONE; // do not attempt to handle failures here, let the next iteration deal with it
     model->params->data.F32[PM_PAR_7] = 0.5/indexGuess[iMin];
-    model->modelGuess(model, source, maskVal, markVal);
+    model->class->modelGuess(model, source, maskVal, markVal);
 
     return true;
@@ -752,5 +752,5 @@
 	model->params->data.F32[PM_PAR_7] = indexGuess[i];
 	
-	if (!model->modelGuess(model, source, maskVal, markVal)) {
+	if (!model->class->modelGuess(model, source, maskVal, markVal)) {
 	    model->flags |= PM_MODEL_STATUS_BADARGS;
 	    return false;