I am at the point in Lost to the Ages where you have to defeat the forge guardians and then the centurion. My Xbox 360 slim (the MW3 one) keeps freezing when there are only 2 master spheres left. I frequently prune saves and have also cleared the cache, as well as reloading an earlier save. Still freezes at the same point in the battle. Does anyone know what I could do the fix this problem? I really hope this is not broken...the only other quest that is broken for me is Blood on the Ice, but that is not causing freezing. Any advice? Thanks.

By the way, it is also known for it to freeze in Dwarven ruins for me. However, the next time I play and pick up from that save, it works fine....