--- a/iro/model/dbdefer.py	Mon Feb 13 22:15:41 2012 +0100
+++ b/iro/model/dbdefer.py	Mon Feb 13 22:16:26 2012 +0100
@@ -32,8 +32,11 @@
         caller=func
         argspec = inspect.getargspec(caller)
         args =[i for i in argspec.args if i != "session" ]
-        sargs=", ".join(args)        
-        sargs+=", session"
+        sargs=", ".join(args)       
+        if sargs:
+            sargs+=", session"
+        else:
+            sargs="session"
         defaults = argspec.defaults
         if not defaults:
             defaults = (None,)