Do I have to run 2 wow server 3.3.0 and 3.3.0a at the same time? Can you answer me why some private server can have both 3.3.0 and 3.3.0a client to join the same realm without any problem?

I have another question. Anyone know how transfer users profile from one server to another? Example: I run server 3.3.0, but now I want to move all users to another server 3.3.0a.