Index: trunk/psModules/src/objects/pmModel.c
===================================================================
--- trunk/psModules/src/objects/pmModel.c	(revision 29004)
+++ trunk/psModules/src/objects/pmModel.c	(revision 30621)
@@ -70,5 +70,6 @@
     tmp->fitRadius = 0;
     tmp->flags = PM_MODEL_STATUS_NONE;
-    tmp->residuals = NULL;              // XXX should the model own this memory?
+    tmp->residuals = NULL;              // do not free: the model does not own this memory
+    tmp->isPCM = false;
 
     psS32 Nparams = pmModelClassParameterCount(type);
@@ -108,6 +109,7 @@
 pmModel *pmModelCopy (pmModel *model)
 {
-    PS_ASSERT_PTR_NON_NULL(model, NULL);
-
+    if (model == NULL) {
+	return NULL;
+    }
     pmModel *new = pmModelAlloc (model->type);