Domain Controllers not replicating user

Hi. We have a Windows 2000 Server with Active Directory and all user accounts setup on it. We recently added another Windows 2003 Server and added it to the forest as a backup domain controller. When you look in Active Directory Users and Computers both servers show identical users so it looks like they are replicated ok. However when you add a new user account on the Windows 2000 Server it does not make the appropriate change on the 2003 Server.

For example I renamed a user account on the W2k Server and changed password, etc. It changes it there. When you switch over to the 2003 Server it still shows the old user there. I thought I’d try to change it there but it tells me the user already exists…so its seeing the change I made on the W2k Server just not showing it on 2003. Does anyone know what I need to do?