Quoting MacFixit:
"G4 crashes on wake from sleep Christopher Coles found that after installing the update on a G4 DP 533 (Digital Audio), if the computer is allowed to sleep, it will crash when awakened. He writes: "I have tried starting up with extensions disabled, but sleep still causes the computer to crash. I also tried starting up from the 9.1 Software Restore CD, however, it still crashes on wake. This problem did not occur prior to the firmware update."
as well as: "Update: A reader writes: "I tend to agree that the firmware updates have something to do with Mac OS X and its BSD kernel. The Public Beta on my bronze PowerBook used to frequently crash with a kernel panic. Under Mac OS 8.6, I used a very old utility called PowerControl from XLR8 by Interex to test RAM. It reported my third-party 128MB module caused errors. When I removed it, Mac OS X no longer crashed."
Fix our Firmware! Petition Dax Dasilva has set up a petition to request Apple acknowledge the "disappearing RAM" issue brought about the most recent updates. Petitions aside, we have heard from several sources (although we still consider the info to be unconfirmed) that Apple is already working on a new update that presumably will fix these issues. "