CD-ROM Drives won't detect disks!

[Rich K]

I have a CD-RW and a DVD drive. Any media in the
drives prior to boot, will give you proper access and
disk application ID and all will appear normal including
opening and closing tray WITH THE SAME DISK. Once any
disk is replaced, the DVD drive becomes completely
inaccessible and the CD-RW drive will act like it doesn't
have a disk loaded.

Device drivers are fine and incicate they are
working properly. These drives had previously been
working for a year and a half...no new hardware. Problems
started when trying to upgrade Nero burning software on
their website. Upgrade appeared to install properly, but
than this started. Uninstalling the programs have no
effect. I've even gone into the registry and deleted any
leftover fragments I could find with the "nero" or "incd"
prefixes. The only way I can get the CDs to work as
advertised is to boot into safe mode. Can't figure out
where the glitch is. I've even reinstalled windows(not a
complete reformat) to see if I can correct the problem.
No luck. I've tried Nero's troubleshooting website, but
don't see anything there.

ANY HELP on where to look would be GREATLY appreciated.
THANKS!