Cd/dvd Not Reading


I have a PowerBook G4 Titanium 400, 3 years old, 768 Mb RAM, 20Gb HD, internal CD/DVD ROM, external FireWire SmartDisk VST CD-RW, external USB iomega ZIP CD-RW, Lexmark Z32 printer, USB scanner.
Problems started after upgrading from OS 10.2.8 to 10.3.5 and incrimental upgrades to 10.3.8 (current). Prior to upgrading to 10.3.5 I backed up as much as possible to CD's using the external SmartDisk VST unit. No problems. No problems prior to this with burning or reading CD's in any of the CD units. Same w/the DVD.
Now, after the OS upgrade, the internal CD/DVD will not read ANY media. The external FW CD/RW will take blank CD's and burn, uning Toast Titanium, but will not read the just burned CD's, unless mounted thru ToastT. I do have two CD's that the FW unit will read and mount - both I believe (not confirmed) to be Windows burned CD's. One is all photos, with a slide show, the other is a homemade audio CD. No other CD's - audio, games, MacAddict, etc. will mount. Also, Sherlock was not working, until I did a log in with items disabled - "Earthlink Total Access" was the culprit there. Sherlock is now working.
I've tried login as another user, login with items disabled, safeboot, checking cables, relaunching the finder, repairing permissions, and reseting PRAM. Also did "fschk" in terminal. Nothing so far has helped.
Any ideas? Will be glad to provide any further info.
Thanks, and have a great Memorial Day.