Novell Client Trust vs MS Firewall

How do I config Microsoft FireWall (MFW)to accept a generel login (Novell Client Trust -NCT) for connecting to a proxy.
When MFW is enabled it don’t allow the NCT to communicate with the proxy, and the proxy then demand a reentering of user and password.
When MFW is disabled there is no problems.

Client Trust IS in the Exceptions List !!!!!