Win 2000 Pro Logon

I have a win 2000 server with active dir. running in a domain, if I freshly install win 2000 pro on a system and it gets to the area that requires the domain info, i include this info in and click next, the system can’t find the domain. If I format and reinstall win nt for workstation run thru the same set up include the domain info, it finds the domain with not a problem. Then I upgrade to win 2000 pro and I have no problems. What is causing this to happen.