AttributeError triggered by i18n.py calling os.path.join with Language object.

Here is the error message in my logs:

Aug 15 18:16:49 2011 (26370) Uncaught runner exception: 'Language' object has no attribute 'startswith'
Aug 15 18:16:49 2011 (26370) Traceback (most recent call last):
  File "/home/sgoss/mailman_clone/src/mailman/core/runner.py", line 138, in _one_iteration
    self._process_one_file(msg, msgdata)
  File "/home/sgoss/mailman_clone/src/mailman/core/runner.py", line 220, in _process_one_file
    keepqueued = self._dispose(mlist, msg, msgdata)
  File "/home/sgoss/mailman_clone/src/mailman/runners/incoming.py", line 64, in _dispose
    process(mlist, msg, msgdata, mlist.start_chain)
  File "/home/sgoss/mailman_clone/src/mailman/core/chains.py", line 90, in process
    link.function(mlist, msg, msgdata)
  File "/home/sgoss/mailman_clone/src/mailman/chains/hold.py", line 190, in _process
    autorespond_to_sender(mlist, msg.sender, language)):
  File "/home/sgoss/mailman_clone/src/mailman/chains/hold.py", line 111, in autorespond_to_sender
    owneremail=mlist.owner_address,
  File "/home/sgoss/mailman_clone/src/mailman/utilities/i18n.py", line 200, in make
    path, fp = find(template_file, mailing_list, language, _trace)
  File "/home/sgoss/mailman_clone/src/mailman/utilities/i18n.py", line 157, in find
    for path in raw_search_order:
  File "/home/sgoss/mailman_clone/src/mailman/utilities/i18n.py", line 74, in _search
    yield os.path.join(path, language, template_file)
  File "/home/sgoss/phoenix-deploy/lib64/python2.6/posixpath.py", line 65, in join
    if b.startswith('/'):
AttributeError: 'Language' object has no attribute 'startswith'