A little while ago my MW2 game disc began experiencing errors. Whenever I load it up, the game seems to work fine. Spec Ops and campaign work great, but whenever I go to play an online multi-player game, it works fine up to when it says "launching" in the game lobby, and then the game freezes. The console will still be fine, but the game has frozen. I tried running it on various accounts, all with the same results. If I join a game that is already playing and it goes straight to the map loading screen, the bar will always go about two thirds of the way, and then it freezes and I need to restart. I can see no cracks or blemishes on my disc. Is there any way I can either fix this or get it replaced?