I've got two computers networked and sharing an internet connection through a router. The network has been working great for transferring files and playing games like Doom 3 and UT2004. The problem is when I try and play Painkiller, Farcry or Quake 1. When I try to run a LAN game with one of the games mentioned above the other computer can't find the started game except right after I've restarted my computer. If I wait too long after restarting my computer or if I play a game and then decide I want to change levels and I restart the server it can't find the other computer anymore (just for those 3 games). I've been trying to figure out what's going on for weeks but havenít had any luck. These games used to work fine on my network before I reformatted both of the computers a couple of months ago. The only things that Iíve done that might make the computers act weird is go through the windows tweak guides at www.tweakguides.com. With that I've tried to go back and change any settings that might be causing the problem but havenít had any luck. If anyone has any ideas it would be much appreciated. Iím running out of things to try and this is starting to drive me crazy. Thx!

Btw, both machines are running WinXP Pro