My girlfriend gave me the game for xmas. And the rest of the story you now very well.
THE FUCKING GAME KEEP FREEZING!!!
I realized that the don't give a damm for post, well, let's try sending messages to Matt ( The guy who wrote the first post, that says the problem is only occurring at xbox 4 GB)
I will be glad if someone create a Facebook page about this. I bet we can find a reasonable numbers of disappointed costumers, and finally make a little noise.