The problem I have is that my liteon 1633 wont read my backup dvd's which I burned on the drive or the blank dvd's that I have, eventhough they worked fine before. It will play original discs, back up cd's etc. Sometimes after reboot and one of the backup discs is in the drive it can be read, but as soon as I eject the disc and insert again it won't read. I have tried unistalling the drive and flashing etc but the problem still remains. I tried the discs in my 5 year old Pioneeer and it works fine. This is my 3rd Liteon and the 1633 is a warranty replacement for another that went a couple of years back. I won't be buying Liteon again they may be cheap but they are cheap crap that aren't built to last eventhough i haven't used the drive that much really. Does anyone have any suggestions, I was thinking maybe I should get a DVD lens cleaner?