Yeah that's probably what happened. There was/is a bug in the tracker that would continuously add and remove a game due to ... magic, or something. It should be fixed, but when you mentioned that problem I immediately thought that was the cause, though I haven't had a chance to go over the logs and figure it out yet. But if you were trying to be MASTER of a game behind that big NAT then it would have looked like the same thing to the tracker and clients, where it would keep disappearing. You could be HOST just fine, since the standalone would do most of the work for you, but MASTER is out of the question.