diff -r f32c50c6b7e0 -r 1daea1f433c9 server/session.py
--- a/server/session.py	Thu Aug 30 17:38:43 2012 +0200
+++ b/server/session.py	Tue Sep 04 06:09:17 2012 +0200
@@ -106,7 +106,8 @@
         self.free_cnxset = free_cnxset
 
     def __enter__(self):
-        pass
+        # ensure session has a cnxset
+        self.session.set_cnxset()
 
     def __exit__(self, exctype, exc, traceback):
         if exctype: