"We have had a persistent problem on our Power Mac G4, where a freeze would occur when waking from sleep. A Force Quit would get things working again, except there would be no sound until the Mac was restarted. Noting various similar symptoms that had been linked to the Apple Audio Extension, we decided to disable this extension. The result: not one wake-from-sleep crash in over a week!
"This is using version 1.0.5 from Apple MultiMedia Update 1.0. This problem has not occurred on an iBook, iMac or PowerBook using same version of the Audio Extension. Either the problem is model-specific or there is some further software on our G4 that is contributing to the problem. In any case, we have noticed no ill side-effects (so far) of having removed the extension.
Note: A newer version of this extension ships with Apple's Summer 2000 Macs. Perhaps these new versions fix this problem."
from macfixit today