I have a G4 Dual 500, 768mb unit which untill 5 days ago was rock solid running OS 9.1 and OS X (10.0). It also had a Pioneer DVR-A03 drive.
Finally making the decision that OS 10.1 was ready for me to move to full time, I bought the full version and reinitialsed my hard disk.
I installed OS 9.2 out of the box, then set about the 10.1 install. Near the end, at the point it is asking me questions, I get a kernel panic. The modules running all seem to refer to ATAPI or similar.
Rebooting the machine, OS 10.1 is working however, if I do any significant CD operations, I again get the panic and have to turn off/on.
I have got the latest firmware, and all software updates, including 10.1.1
I have reinitialised 4 or 5 times, same issue on all occasions. Apple are not being helpful, saying it must be the DVR-A03 causing trouble as it is not sold by them.
Incidentally, for the past 2 days I have just not put a CD in the drive - the machine is rock solid and running great. Of course, I can't do that forever!