I'm trying to play this game with 2 people. We can both host the game without a problem, but whenever either of us try to join a game, the window saying "connecting" appears and after a while, it goes back to the main screen. Both computers are Windows 64bit and there doesn't seem to be any issues with the firewall. I've encountered this problem with more than one person. What might be the problem, and are there any fixes available? Thanks.