Mod_python error: "PythonHandler mod_python.cgihandler"

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/lib/python2.3/site-packages/mod_python/cgihandler.py", line 102, in handler
    apache.restore_nocgi(env, si, so)

UnboundLocalError: local variable 'env' referenced before assignment