Call of Duty 4 online broken?

I ws playing call of duty 4 the last couple of days, and it worked great yesterday and the day before that, but today, whenever I join a game, and the lobby transtitions into the match, as soon as 'match beginning' countdown is over, it immediately takes me to a black screen that says nothing bu awaiting connectiong...0... and never moves past there. If I try to exit the game via the XMB, my ps3 slowly shuts off. The game runs completely smooth otherwise and EVERY other game online works perfectly.