When I try to play with two computers at my friend's house we can't. Both computers can surf. We will both detect the game that has been created, but we keep getting the message "unable to join". We both can join different games on zone.com but not the same game. When we try to connect on the lan without zone.com it doesn't work either. I can take the laptop to my house and it works fine. Why can we detect the game on the lan but not join it?

Zone is dead.

The problem could be caused by a firewall. Also you might want to check out a utility called DXPort that will allow an allocated a range of ports to be shared between 2 or more clients when they are join in a game over different network(s) (e.g. the Internet).