=== modified file 'main/Control.py'
--- main/Control.py	2007-06-23 12:09:42 +0000
+++ main/Control.py	2012-02-27 19:32:58 +0000
@@ -32,7 +32,13 @@
 
         lst = self.__handlers.get(prop, [])
         for handler, args in lst:
-            utils.run_in_main_thread(handler, getattr(self, prop), *args)
+            try:
+                is_callable = hasattr(handler, '__call__')
+            except NameError:
+                is_callable = False
+
+            if (is_callable):
+                utils.run_in_main_thread(handler, getattr(self, prop), *args)
 
 
     def bind(self, prop, handler, *args):