moving sbs2000 to windows 2003 server

hi guys,

i am trying to move away from sbs to a standard win 2003 srvr.

initially are main server was sbs 2000, we upgrade AD and installed win 2003 svr as DC.

i moved all the fsmo roles to win 2003, moved dns, dhcp and made the win 2003 svr GC.

i want to finnally turn off the sbs 2000 server,
when i do, i get errors adding users to workstation: ie trust relationship between pdc and workstation failed.

am i missing something?