I've had similar problems with other games, my NFSMW disc is used so it hangs every once in a while but its all scratched. My oblivion disc was brand new and a christmas gift and I got to play to after the sewers and then the game went to shit and couldn't load my saves. I talked to the online store, the store where my parents bought me the CE of Oblivion which ended up being in Canada and sent it back lol. Have the game and it works fine, it was the disc and I heard of these symptoms on other games over at the xbox forums. My advise, replace your disc, its not the 360 likely, go on a movie marathon as well.