This same thing has been happening to me. What the F is it? Let me know what you find out.
so after checking the Xbox support, which my iPhone cant access. It asks for a user name and pw? huh?
There is a step by step trouble shoot for freezing issues. Started the process and found out that it's my HD. It's corrupted and need replacing. So if your game keeps freezing or disc errors try playing the game with the HD removed. If it works then guess what, time for a new HD. Contact Xbox Support they might be able to replace it.
~Lycane