Mod_python error: "PythonHandler nav.web.messages.handler"

Traceback (most recent call last):

  File "/usr/lib/python2.3/site-packages/mod_python/apache.py", line 299, in HandlerDispatch
    result = object(req)

  File "/usr/local/nav/lib/python/nav/web/messages/handler.py", line 85, in handler
    for i, msg in enumerate(page.msgs):

TypeError: iteration over non-sequence