Cannot authenticate with Exchange 5.5

I am currently running Exchange 5.5 on a NT 4.0 server within a Novell environment using XP Pro and Outlook 2000. When attempting to login to Outlook I receive the notice that the "Logon credentials supplied were incorrect." Currently the only waythat I can authenticate with Exchange is if I manually set my password on the server. If I use the current password or if I change the password, I receive the error message mentioned above. What is strange is that I have tryed loging in while not joined to the domain as well as while I was joined to the domain. When joined to the domain I can authenticate with the domain upon initial logon to the netowrk but when I try to authenticate with exchange I receive the same error message. As I stated I have tried with and without being joined to the domain, with or without the Novell client installed, rebuilding my email profile, verifying RPC registry settings, adding the exchange password info through "manage my network passwords" in XP, using LMHOST files, as well as verifying NGP settings on the server. I also currently have 98 clients using Outlook 2000 which have no problem accessing exchange.