500 Internal error

The server encountered an unexpected condition which prevented it from fulfilling the request.

Page handler: <bound method Root.feedtest2 of <feedtest.controllers.Root object at 0x8bf520c>>
Traceback (most recent call last):
  File "/home/chris/lib/tg-py25/lib/python2.5/CherryPy-2.2.1-py2.5.egg/cherrypy/_cphttptools.py", line 105, in _run
    self.main()
  File "/home/chris/lib/tg-py25/lib/python2.5/CherryPy-2.2.1-py2.5.egg/cherrypy/_cphttptools.py", line 254, in main
    body = page_handler(*virtual_path, **self.params)
  File "<string>", line 3, in feedtest2
  File "/home/chris/tmp/build/turbogears/branches/1.0/turbogears/controllers.py", line 344, in expose
    *args, **kw)
  File "<string>", line 5, in run_with_transaction
  File "/home/chris/tmp/build/turbogears/branches/1.0/turbogears/database.py", line 307, in so_rwt
    retval = func(*args, **kw)
  File "<string>", line 5, in _expose
  File "/home/chris/tmp/build/turbogears/branches/1.0/turbogears/controllers.py", line 359, in <lambda>
    mapping, fragment, args, kw)))
  File "/home/chris/tmp/build/turbogears/branches/1.0/turbogears/controllers.py", line 399, in _execute_func
    return _process_output(output, template, format, content_type, mapping, fragment)
  File "/home/chris/tmp/build/turbogears/branches/1.0/turbogears/controllers.py", line 86, in _process_output
    fragment=fragment)
  File "/home/chris/tmp/build/turbogears/branches/1.0/turbogears/view/base.py", line 131, in render
    return engine.render(**kw)
  File "/home/chris/lib/tg-py25/lib/python2.5/Genshi-0.4.2-py2.5.egg/genshi/template/plugin.py", line 99, in render
    return self.transform(info, template).render(**kwargs)
  File "/home/chris/lib/tg-py25/lib/python2.5/Genshi-0.4.2-py2.5.egg/genshi/core.py", line 153, in render
    generator = self.serialize(method=method, **kwargs)
  File "/home/chris/lib/tg-py25/lib/python2.5/Genshi-0.4.2-py2.5.egg/genshi/core.py", line 189, in serialize
    return get_serializer(method, **kwargs)(_ensure(self))
  File "/home/chris/lib/tg-py25/lib/python2.5/Genshi-0.4.2-py2.5.egg/genshi/output.py", line 69, in get_serializer
    'text':  TextSerializer}[method.lower()]
KeyError: 'html default'