The snowy map works for me when joining other games, if you can host with it then it is properly installed and you should be able to join other's game with it. Look for someone hosting a dm/snowy (not many). By the way, I also have the intel 810 chipset and it is crap. Actually, I have it on 2 of my machines but I installed a PCI video card in the other one because the chipset is easily bypassed if you want to upgrade.