I have a problem with my dvd drive. , liteon 851s, dvd rewriter, plays cd's and burns cd's but won't play or burn to dvd. I uninstalled drivers and rebooted , all test ok in device manager. Did flash update to gsop. Nero info tool shows as master, also have liteon cd burner /dvd rom which has no problems at all. Don't know why it won't see a dvd. any help is appreciated. Tried changing ide cables, disconnecting other burner, checked in bios,all good.