BenQ-DW1655 has quit reading/opening CDs

My BenQ-DW1655 has suddenly quit reading and opening CDs. I'm running Windows XP Home, plenty of power and RAM. It will read and open DVDs fine, but won't open CDs.

Let me explain: When I insert a CD, AnyDVD scans it, Autoplay scans and I can see the contents flash along as it scans, the Open With window comes up, but when I attempt to open or explore, nothing happens. I've even uninstalled and let Windows find it again. I'm running the latest firmware (BCIB). The volume name will even show up fine under My Computer. The CD will just not open in the BenQ. Yet the CDs will read and open fine in another drive.

I've scanned for viruses, worms, corrupt registry entries, etc.

Any suggestions? TIA!

Edit: Even with no disc in the drive, a mouseover indicates Free Space: 0, Total Size: 139MB. It can read a bootable CD (I use Ghost once a week) and will boot from the CD. In Windows is where my problems lie.