setting up w2k ws on different sub net

we have been allocated a new subnet(B) to as the other subnet(A) has filled up. The NT server (NT 4) – primary and backup is on subnet A and I have setup wins on both servers. The dns has all been setup and is working fine. But when I setup the w/s with subnet b address to join the domain I get the msg. “The specified domain either does not exist or could not be contacted”.
Now I can ping any machines from this workstation which implies the dns and dhcp (are setup on unix) settings are correct.