Problem joining 2000 Server domain

Hi,

I have a network which has moved to 2000 Server. One of the workstations, running 2000 Professional, has joined the domain without problem. I have set up a new 2000 Pro w/s, with seemingly identical configuration, and when I try to join the domain, it says it cannot find it.
NSLOOKUP correctly locates the name server. I don’t have enough experience to know what to do next. Incidentally, if I try to join a WORKGROUP with the name of the DOMAIN, I can see all the other machines.

Thanksand regards….Chris