I have the Lite-On SHW 1635S but in my case it reads DVDs but ignores CDs. I have updated the firmware for it but that didn't make a difference.
The CDs I use work when I use them on a different drive but the Lite-On fails to identify any type of CD media ( blank/audio/proprietary/CD-R/CD-RW)
Strangely enough, it has no problems with DVD media and I don't understand why this happens when I use CDs.
I have checked the connections and reconnected the IDE ribbon cable and even replaced it with a new one but that didn't resolve the problem either.
Any ideas or is it a case of sending it back for a new one as it's still under warranty ?