Mod_python error: "PythonHandler mod_python.publisher"

Traceback (most recent call last):

  File "/usr/lib64/python2.4/site-packages/mod_python/apache.py", line 299, in HandlerDispatch
    result = object(req)

  File "/usr/lib64/python2.4/site-packages/mod_python/publisher.py", line 213, in handler
    published = publish_object(req, object)

  File "/usr/lib64/python2.4/site-packages/mod_python/publisher.py", line 412, in publish_object
    return publish_object(req,util.apply_fs_data(object, req.form, req=req))

  File "/usr/lib64/python2.4/site-packages/mod_python/util.py", line 439, in apply_fs_data
    return object(**args)

  File "/soft/http/htdocs/MaKaC/conferenceCreation.py", line 31, in index
    return categoryDisplay.RHConferenceCreation( req ).process( params )

  File "/usr/lib/python2.4/site-packages/MaKaC/webinterface/rh/base.py", line 479, in process
    res = self._processUnexpectedError( e )

  File "/usr/lib/python2.4/site-packages/MaKaC/webinterface/rh/base.py", line 318, in _processUnexpectedError
    return p.display()

  File "/usr/lib/python2.4/site-packages/MaKaC/webinterface/pages/base.py", line 131, in display
    return "%s%s%s"%( self._getHTMLHeader(), \

  File "/usr/lib/python2.4/site-packages/MaKaC/webinterface/pages/base.py", line 168, in _display
    return self._applyDecoration( self._getBody( params ) )

  File "/usr/lib/python2.4/site-packages/MaKaC/webinterface/pages/base.py", line 165, in _applyDecoration
    return "%s
%s%s"%( self._getHeader(), body, self._getFooter() ) File "/usr/lib/python2.4/site-packages/MaKaC/webinterface/pages/base.py", line 152, in _getHeader return wc.getHTML( { "loginURL": self.getLoginURL(),\ File "/usr/lib/python2.4/site-packages/MaKaC/webinterface/pages/base.py", line 139, in getLoginURL return urlHandlers.UHSignIn.getURL("%s"%self._rh.getCurrentURL()) File "/usr/lib/python2.4/site-packages/MaKaC/webinterface/rh/categoryDisplay.py", line 147, in getCurrentURL url.addParam("event_type", self._event_type) AttributeError: RHConferenceCreation instance has no attribute '_event_type'