[Zope] No Authorization header found

I have try to install Zope 2.0.0.a1 using Apache web server on Redhat Linux 5.2, however I am getting the error message as below : - Traceback (innermost last): File /usr/local/src/Zope-2.0.0a1-src/lib/python/ZPublisher/Publish.py, line 255, in publish_module File /usr/local/src/Zope-2.0.0a1-src/lib/python/ZPublisher/Publish.py, line 145, in publish File /usr/local/src/Zope-2.0.0a1-src/lib/python/ZPublisher/BaseRequest.py, line 414, in traverse File /usr/local/src/Zope-2.0.0a1-src/lib/python/ZPublisher/HTTPResponse.py, line 540, in unauthorized Unauthorized: (see above) Best regards; Tee How Long