Try running the game through x360GameHack to remove any AP Protection.
Also, if you ahve the disc, why not install the game to hard drive in NXE and use NXE2GOD to convert it. Should resolve this issue?
Another thing, make sure you use the USB at the back, as the back USB Ports have their own dedicated SystemBus, where as the 2 at the front share one systembus amongst other things on the board.