I had the exact same issue, where my drive's DVD section stopped working. But the cause was a bad version of firmware, ersion 0039, which cause the DVD portion of the drive to burn out. With your replacement drive, assuming you had a recent firmeware, this should not have happened again. You may want to try booting in DOS mode with CD rom support, and see if the drive sees DVD's. That is a good way to test the DVD portion of the drive.