Interesting problem... I assume you don't get a fixed IP from your ISP? It's perfectly normal for you IP to change when you disconnect and reconnect, i.e. when you terminate the session, but this should not happen while you are connected. Perhaps do the following: Check what your external IP is before you start playing, then if you get booted, check to see if it has indeed changed. If so, you need to take it up with AT&T.