DVD RW stopped reading data & music CDs

My standard DVD RW (a Lite On dvdrw lh 20a1h ata, for what it's worth), used
to work fine under Vista Ultimate, but recently (2 months since Jul/Aug07)
has stopped reading music and data CDs. It still reads DVDs fine.

But when I put a music or data CD in the drive, nothing happens, and when I
launch File Explorer to look at the drive, it whirs (a little) for a while,
then either ejects the CD, or pops up "Insert Disk," as though it only
expects me to want to burn a disk.

I done all the registry Upper and LowerFilter deletes suggested by MS,
updated drivers, updated drive firmware.

Seems it may have been caused by a recent Vista update.

Any thoughts?