XP Pro Workstations and a W2K Server

I have 12 XP Pro workstations, 15 Win 98se workstations, a win 2000 file server/domain controller and a win NT domain controller.
I’ve never had any problems with win98 workstations but I am having no end of grief trying to get the XP machines on the network. So far I’ve successfully got 2 on it but I haven’t intentionally done anything different on them.
XP machines work perfectly well whilst they are controlled by server1 (the NT server) on domain1 but they wont work (except those 2) on server2 (win 2000) on domain2. Can anyone help