So, the problem me and my mates are having, is we are all sitting in a room trying to play some DG. One of us will host a game, and the others will join it. The first three players get into the game 'fine' and the 4th sits in limbo unable to finish connecting. He will occasionally 'be connected' to each person in the game, but never make it tot he game lobby.
Note that we have all had no problem individually connecting and playing games (At least, not more so than anyone else).