My friend does have similar problem before and what he did is clear Xbox system cache, then delete Title update for Ghosts and re-download it. It worked for him. You may try it too. By the way, if the same thing happened, you may test the game on a different Xbox 360 and see if the problem remains. If the game works on a different Xbox then there might be an issue with your console but if it does not work on other console then it may be a disc issue. Hope this help you.