CD-ROM not working

I have had a TDK 40x cd burner for several years, and it's been working fine. I'm running Windows 2000 Pro w/SP4.

I can burn CD's with no problem, but can't read any CD. Doubleclicking the CD icon in My Computer gives a "D:\ not accessible, incorrect function" error. When no CD is in the drive, I get the normal "Please insert CD..." message. Also, no virtual drives work, like from Daemon tools or the like. They all get the same error. Now, going to Nero InfoTool thing says all the ASPI are installed (both Sytem and Nero), yet my computer won't read a CD.

This might have started after I updated Nero, but Nero works and my system can't read any CD. Anyone know what the problem is?