I have just been kicked out of a friend's "friend only" multiplayer game several times from the lobby, waiting for the game to start. I also can't install disc one. It never gets past 3%. When I first got it, I installed it just fine but couldn't properly progress through campaign without getting kicked back to the main menu and/or losing credit for completed chapters of the campaign. I uninstalled disc one, per some instructions I found in a forum discussing problems with the campaign. I stopped having issues there but have never been able to play more than two chapters of Spartan Ops back to back and usually get kicked out when trying to start a chapter. Disc two is installed, obviously but disc one will not re-install. I wonder how many of you can observe a strange, uneven area of different coloration on the data layer of your disc. If you look at the unlabeled side and slowly tilt the disc, you should be able to see it, if it's there. I'm beginning to think a lot of these issues that seem, on the surface, to be network or server problems, are really the result of defective play discs (disc one). Perhaps it's part of some digital rights management thing. It could be that their servers are attempting to verify my copy of the game is legal and failing because the disc is messed up. It would also explain why the majority of people seem not to be having a problem, while a sizeable minority is having pretty much *identical* issues.