Actually, I had the exact same problem. I would load up one of my saves, then everytime I leave the screen to another area it would freeze. This is another common problem. I have it autosave. So, basically when it saved, it would then freeze. I had to delete the autosave file to get it to work, that's all.

I remember I was almost done with the game, near the end. The game froze as I was walking into a building, or at last it seemed to freeze. I opened the disk tray, then closed it. Surprisingly, it loaded and kept going without having to reset the xbox. Unfortunately, my total gameplay hours jumped intp the millions.

even the original dvd wont boot up.... i thought it was my xbox but i tried other games and they work fine... so ima borrow my cousins xbox and try to back it up on his then transfer to computer n make an image from that... hopefully i get some luck this time