I did the update and it messed up my G4 dual 1.0.1
I hit restart after the update was done and it shutdown, did the ding and then turned off.
I started in cafe la, but realized it would benefit more here.
To get the computer to stay on, I had to remove the Radeon 9800 Pro card and put my old card back in, starts up just like it used too.
I am going to call apple and ati in the morning to figure out if it is a bad card or if I need a new driver.
Darren