I did have the problem with the XP when the game first came out. I stayed up trying to unlock the select fire for the FAL. The next day I got the file corrupted message and all my progress was gone. The same damn thing happened to me a total of 4 times.
Maybe I'm just paranoid now, but when I am done playing I back all the way out to the main menu, dashboard and then shut off the xbox to make sure that any files that need to be written are written properly and not corrupted. I guess I just though maybe shutting down the xbox without backing out of the game was interrupting my files being written, and therefore corrupting them. Since doing this I haven't had any problems with corrupt files.
May be strange, but if it works....
This post was edited on 1/29 at 4:11 pm