I've tried everything on this website http://www.revoltrace.net/help.php and I still can't get the game to work. When I try to join a game in RV house it launches it but then the screen turns black and the game crashes. The game works fine in sp and I can even host games with no problem. Any ideas?
Does the game specificially "crash"? Or do you get an error message?
You say that you can host games, but has anyone been able to join the hosted game? Do you own a router? A firewall?
Other information such as Operating System and the version of Re-Volt could be very useful to determine what is wrong.