Not able to connect to a 2003 server

I joined a workstation to the domain running Window XP sp2. I was then unable to connect to a server (Windows Server 2003 R2 Enterprise x64 sp2) in the domain; I get a login prompt when I try to connect. I supply my information (user and Admin) but I get nothing. So I then removed the workstation for the Domain and added back, I was then able to access the server. This is the only server having this issue. This has happened on two separate workstations, on the first after adding back to the domain it lost the ability to connect to that server again. Also when I rejoined the workstations to the domain, I changed the computer names. This only seems to happen to machine recently joined to the domain; any help would be greatly appreciated.