[Zope] Problems using zope as a xml-rpc server

Hello Zopistas, I'm trying to implement a xml-rpc server with zope. If I try to retrieve a default “index_html” from python with xmlrpclib there is no problem, but if I try to retrieve a dtml method with a zsql method inside it responds: xmlrpclib.ProtocolError: <ProtocolError for ntserver:8080/RPC2: 401 Unauthorized>. I test the BasicAuthTransport class from the “XML-RPC How To”, but it crashes with error: NameError: encodestring. After this I changed encodestring with base64.encodestring, the same result (Unauthorized). Any ideas? Thanks in advance.