Issue with Vista?

[Hotwired]

I have FileMaker 8 server that hosts databases using Active Directory for access rights. My clients have been accessing the hosted databases without any issues. We use both Macs and Windows and have never had a problem, until one of my users upgraded to Vista.

He has Vista Ultimate installed. The workstation is part of the AD domain and he is logging in to the computer with his AD credentials. When he tries to open a remote file hosted on our server, instead of passing his credentials to the FMPro server and using them, he is prompted for a username and password. Nothing works AND his account in AD is LOCKED! Even if he doesn't try to put in his username and password, it locks his account as soon as he tries to access the host server.

His account works with all other versions of Windows and FM running on a Mac OS X.

Something else, he was previously using Vista Ultimate RC1 and he was able to access the databases with no problems.

I tried updating his client with the v2 update...also tried uninstalling and reinstalling. Nothing seems to work.

Any Ideas??