I'm a Java programmer, not too big on my PHP knowledge.

I'll take a look through those two files though, as a place to start.
One question that sticks in my head though....let me run through a quick set of steps:
User logs in to client application
Client contacts main server with login info
Server validates username/password
Can the main server then hit the forums server with a login request for the user?
My knowledge of sessions and cookies isn't as good as it should be, but I'm thinking that the client would have to hit the forums through it's embedded browser in order to get the session information set up properly. I could be wrong though (it's happened once or twice before).
I'm assuming we'll be able to do the user registration and profile editing from the server, but that the logging in and out will have to come from the client.
Thanks! I'm sure I'll have more questions tomorrow....