System wont play Cd's or DVD's

I have been running W7 on this box since W7 came out. I use the TV tuner, Dvdfab, play movies, rip cd's and to this point haven't really had any problems. About 2 weeks ago I was unable to open a movie to use DVDFab to copy it. DVDFab had expried. I did upgrade to the latest version, but that didnt help. Then I tried playing a CD. No luck there either. CD will not play. WMP just sits at the blue circle. Sometimes it will recognize the cd and songs, but no music. It will play movies and cd's already on the drive, so mp3, itunes, MCE movies, you tube...no problem. Only physical cds and dvds. Same problem if you try and play them from WMC. Thinking it was a problem with the DVD drive I booted with an old copy of UBCD and it worked fine. I have checked for virus, malware, uninstalled Dvdfab and any other extraneous programs, have tried going back to system restore points as far as I could. I have run the troubleshooter, perfmon, EV....I can't find anything wrong except when I try to do those two things. What do you think I should do next? Replace DVD player? Reload Windows 7 (which I would like to avoid doing)?

Box is Shuttle w AMD dual core, 4 gig ram, W7 Pro, LG DVD.

Buehller? Buehller?