Win2k Migration

I’m migratiing to Win2k from an NT 4.0 domain. I have successfully upgraded the primary DC to Win 2k. I have three BDC’s that still need migrating. I’m still obviously running in mixed mode. My problem is that I’m trying to add a Win2k server as a bdc for the domain. It has a clean install of Win2k and is a dual xenon rig. But so far when I try to activate active directory I get an error message stating that a domain controller for the domain can’t be found. DNS and Wins are running on the PDC.Do I have to migrate my other servers first and switch to native mode or is this possible? Any suggestions would be greatly appreciated.