I have a problem accessing a Windows Server 2003 R2 machine which is a domain controller. A domain admin account is logged in and the screen saver has activated, but bringing up the "Unlock Computer" dialog and entering the username and password results in the "Computer Locked" dialog with the message "This computer is locked. Only domain \ username (username) or an administrator can unlock this computer." The username entered is the same as the one that has it locked, but the error dialog suggests the machine thinks it's not the same user (an incorrect password would give a different error, no?)
Interestingly, the "Log on to:" dropdown in the "Unlock Computer" dialog contains lots of blank lines i.e. the domain the user belongs to is not there.
I have tried entering domain \ username for the username, but this gives the same result.