I have an older modded xbox and recently the dvd drive started not recognizing disks. I purchased an identical replacement drive and installed it. It works fine with my original games, but it will display "unknown" when I try to play my backup game disks. Has any one heard of this problem???? Please HELP!!!! And, if I load the original MS dashboard it comes up with a message saying that there is a problem with the xbox and I need to contact customer service. It started displaying this message before I changed the dvd drive.