We have DSFW setup and I am trying to setup a couple of windows boxes so that users and group policy can be managed. If Windows XP is used, 'Active Directory Users and Computers' connects fine and the directory can be browsed. If Windows 7 or Server 2008 is used I can login to the machine (it is joined to the domain) but I can't access the 'Active Directory Users and Computers' application, I get the following error...

Naming Information Cannot be Located because:
Login Failure: unknown username or bad password

I know the login credentials are correct, as I logged in fine. The PC time is in sync with the server time. I had no errors when joining the PC to the domain, the PC appears under the 'Computers' container. The DNS settings on the XP machine and the Windows 7 machine are the same.

Any help is much appreciated.