diff -r ba136820dd7d -r a822b0b64252 plugger.py
--- a/plugger.py	Wed Dec 16 15:09:12 2009 +0100
+++ b/plugger.py	Wed Dec 23 22:23:02 2009 +0100
@@ -1261,7 +1261,7 @@
         """
         self._ProgramList = None
         self._VariablesList = None
-        self._IECPathToIdx = None
+        self._IECPathToIdx = {}
         self.TracedIECPath = []
 
     def GetIECProgramsAndVariables(self):