I have a very basic network setup with one 2003 Server running AD and several member servers, one of which is running Exchange 2003. Until last week I was able to use ADUC to modify and create users from the Exchange server. Since last week I can only view properties. It doesn't give me any choice to create users, and all user properties are greyed out. If I try to do anything it says "you do not have permission to change the [whatever] attribute, changes will not be saved."
I am logged in as administrator, and I rebooted this server this weekend. I have not rebooted the primary server yet.