Wierd LAN Issues

Alright.

My friend and I have a wireless network at his house. He has a desktop computer, and I have a laptop. His computer is connected to the router, and my computer connects via wireless. We're both running windows XP, we're both on the same workgroup. I can ping his ip using run>>ping 168.168.0.1 and we can even transfer files from one computer to the other.

The problem arises whenever we try to play any sort of multiplayer game over LAN. We've tried FarCry, Unreal Tournament, Doom, and a few others. One of us will create the game, and then start the server, but when the other goes to join, it doesn't show up in the list of LAN games at all. Even connecting directly to the IP won't work. I have no clue what to do anymore. I've tried playing around with the router settings, and various other settings but to no avail.

Any insight into this issue is greatly welcomed. Thanks in advance.

Jam it back in, in the dark.