Cant add computer to WIN/2000 Server PDC

Hello all, I have a new windows 2000 server,and I migrated from Win /nt 4.0 domain. I have two domains 1 and 2, and the migration went well except, I have all my machines in the new domain but it will not let me add any new machines. I have to add it to the old domain first (both domains are trusted) then move it to the new. I am new to win2000 server, please help if you can.
Thanks