500 Internal error

The server encountered an unexpected condition which prevented it from fulfilling the request.
Page handler: <bound method Root.authenticator of <ldapadm.controllers.Root object at 0x1b1fb50>>
Traceback (most recent call last):
  File "/usr/local/lib/python2.4/site-packages/CherryPy-2.2.1-py2.4.egg/cherrypy/_cphttptools.py", line 105, in _run
    self.main()
  File "/usr/local/lib/python2.4/site-packages/CherryPy-2.2.1-py2.4.egg/cherrypy/_cphttptools.py", line 254, in main
    body = page_handler(*virtual_path, **self.params)
  File "<string>", line 3, in authenticator
  File "/usr/local/lib/python2.4/site-packages/TurboGears-1.0.1-py2.4.egg/turbogears/controllers.py", line 131, in validate
    form = init_form(args and args[0] or kw["self"])
  File "/usr/local/lib/python2.4/site-packages/TurboGears-1.0.1-py2.4.egg/turbogears/controllers.py", line 124, in <lambda>
    init_form = lambda self: form(self)
  File "/root/tmp/orgldap/LDAPAdmin/trunk/ldapadm/controllers.py", line 99, in get_create_form
    user = self.create_user()
  File "/root/tmp/orgldap/LDAPAdmin/trunk/ldapadm/controllers.py", line 67, in create_user
    args = convert_args(cherrypy.request.params)
  File "/root/tmp/orgldap/LDAPAdmin/trunk/ldapadm/controllers.py", line 580, in convert_args
    v = convert_args(v)
  File "/root/tmp/orgldap/LDAPAdmin/trunk/ldapadm/controllers.py", line 578, in convert_args
    v = str(v)
UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-9: ordinal not in range(128)