I did think of one (or two) other thing(s) you might want to look at...
Certain Nero Serial Numbers force Nero into OEM mode, meaning that Nero came with a particular drive as a package deal. This would prevent you from choosing an alternate drive as the recorder. It may be that your OEM version didn't play nice with upgrade, or vice versa.
Also, what are the chances that you are running Nero Enterprise? If so, maybe some of the burn options you are using are not compatible with the drive.
I myself have the Pioneer 105/A05 (assuming that is what you meant instead of Panasonic). I am running one version under the latest of Nero with no problems.
And if it is the Pioneer 105 you have, have you flashed the firmware to 1.30? Did you flash it with the hack that allows you to write Ritek 1X at 2X (also known as the "region free" hack)? If so, flash back to Pioneer's original 1.30.
Let us know.