Well, you have to make sure you're domain and forest functional levels are not in 2K mixed mode. I think you can be in 2K native or 2K3. You can't have any NT boxes on your domain. 2K and above only. See the following for more info. http://technet.microsoft.com/en-us/l.../cc754918.aspx

That's all that I had to do. I'm in the process from migrating from Netware to AD but 2K3 was my first DC. Then I added two other 2K8 DCs using the same process above. You're gonna love 2K8. I'm already hating 2K3 after having used 2K8. GP extensions are great!