Originally posted by Genocide47
I don't know how it changes your NAT to open but what he's trying to say is If you have MW2 then put it in and load up multiplayer, find a game and then back out.
You load up MW2 and then go on multiplayer then it should say NAT TYPE: OPEN join any game E.G... team deathmatch, capture the flag.... then leave that game and put your black ops disc in and your NAT type should be OPEN...
Try it... it works