Call Of Duty 4 Game Help and Maps ⇒ Little tip

[Gen Stranger]

I doubt it was evenbalance that caused that problem
Sounds more like activision (the game itself)
Evenbalance is Punk Buster and Call Of Duty 4 is no longer supported by them.

[Gen Stranger]

I believe when you disconnect from a server the server sends a packet to the client to notify the key has been 'released', so to speak. That's why there were those nasty servers where they were stealing peoples cd keys, they were exploiting this system. It's likely when you switch networks midgame this process is not happening, so the server is not technically recognising you as having left, ergo won't authorise you for entry again.

I had that happen to me once when my game crashes and I tried to re-enter
I had to reboot the computer and finally was able to enter again