Can't shutdown my PowerMac after updating firmware


Have any one come across this problem that after updating firmware, my os x refuses to shutdown and restart?

PowerMAC G4/400/20GB/256MB/
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. "
This may help...but I'm still avoiding the firmware update on my machine - thank God , there's a forum like this...:

"Possible solutions We have already posted several reader suggestions for solving this problem. None seems universally successful. So here are some more:

Turn off Startup Memory Tests Several readers suggested that disabling the Memory control panel's startup tests may resolve the problem. To do this, hold down the Command-Option keys when you launch the control panel. A new option called Startup Memory Tests will appear. Click to turn the option off.

Data Memory System (DMS) has a web page where they suggest that turning memory tests off before you install the update may actually prevent the problem in the first place. After the firmware update has been installed, it will be okay to turn the memory tests back on. (Thanks, John Protopapas.)

Swap slots: Eric Wolbrom had the memory loss problem in his Pismo PowerBook. he solved it by swapping the memory cards, moving the original card to the third party slot and vice versa.