--- a/PLCControler.py	Mon May 21 18:49:49 2012 +0200
+++ b/PLCControler.py	Mon May 21 18:50:16 2012 +0200
@@ -397,7 +397,8 @@
             edit = debug = pou_type is not None
             if pou_type is None:
                 block_infos = self.GetBlockType(var_type, debug = debug)
-                pou_type = block_infos["type"]
+                if block_infos is None:
+                    pou_type = block_infos["type"]
             if pou_type is not None:
                 var_class = None
                 if pou_type == "program":