diff -r c91e6a74a4bc -r 349fa0e3e253 src/python/importer.py
--- a/src/python/importer.py	Thu May 02 12:19:02 2013 +0200
+++ b/src/python/importer.py	Thu May 02 12:19:11 2013 +0200
@@ -54,8 +54,7 @@
         import imp
         import os
         import sys
-        mod = imp.new_module(fullname)
-        sys.modules[fullname] = mod
+        mod = sys.modules.setdefault(fullname, imp.new_module(fullname))
 
         try:
             mod.__loader__ = self
@@ -68,6 +67,9 @@
 
             if os.path.basename(srcfile) == '__init__.py':
                 mod.__path__ = fullname.split('.')
+                mod.__package__ = fullname
+            else:
+                mod.__package__ = fullname.rpartition('.')[0]
             mod.__file__ = srcfile
 
             exec code in mod.__dict__