help no two player co-op mw2 !!!

[henryford]

hi all, it seems since i installed a belkin wirless router i can no longer join a two player co op game on mw2.. when my freind try to join my game it says can not connect or host error and the same when i try to join his game. the multiplayer on line and all other games are fine. are there settings in the router setup i need to change to allow co-op ?? ( my rig is hard wired into the router )

thanks for any help

win 7 32bit
gigabyte p35 3sdl
e4300@ 2.6gh
freezer 7 pro
4gb pc6400
ati 4870 1gb
logitech 5.1
x-fi music