This has happened twice on another system of mine: G4 400 (AGP)...
While in the System Preferences "App / Control Panel " the proccess crashes, then the desktop proccess would stop and the finder icon in the dock would keep bouncing... and bouncing .. and bouncing.. everything else was not effected, but I could not open a finder window nor system preferences... after a reboot.. still bouncing, and bouncing... with the purple/blue background, but the dock still loads and anything on the dock will still work, just not finder/desktop because it's still bouncing... and bouncing in the good `oL dock there.....
The only way I got it all back was performing a clean install, where as doing a re-install on top of the current installation yielded no fix.
I think, that is I have the intuitive idea, that when the System Preferences app crashes, it damages a preference file per-haps, and the finder / desktop proccess has trouble opening and keeps opening and finding an error then closing then opening all over again, it looks as if the finder/desktop proccess is set for a loop... And the bug is, it does not self repair the preferences file(s) or has a default setting in case of errors.
I did not think about this until after the second clean install, to fish around and see if there is actually a preference file, that I could have deleted when all this happened and perhaps the finder/desktop created a new one and would launch properly... it's all just a theory... but be warned, if what ever it is happens... you may need to do a clean re-install to get it working again, unless there is a trick with a "Peferences" file somewhere.......
While in the System Preferences "App / Control Panel " the proccess crashes, then the desktop proccess would stop and the finder icon in the dock would keep bouncing... and bouncing .. and bouncing.. everything else was not effected, but I could not open a finder window nor system preferences... after a reboot.. still bouncing, and bouncing... with the purple/blue background, but the dock still loads and anything on the dock will still work, just not finder/desktop because it's still bouncing... and bouncing in the good `oL dock there.....
The only way I got it all back was performing a clean install, where as doing a re-install on top of the current installation yielded no fix.
I think, that is I have the intuitive idea, that when the System Preferences app crashes, it damages a preference file per-haps, and the finder / desktop proccess has trouble opening and keeps opening and finding an error then closing then opening all over again, it looks as if the finder/desktop proccess is set for a loop... And the bug is, it does not self repair the preferences file(s) or has a default setting in case of errors.
I did not think about this until after the second clean install, to fish around and see if there is actually a preference file, that I could have deleted when all this happened and perhaps the finder/desktop created a new one and would launch properly... it's all just a theory... but be warned, if what ever it is happens... you may need to do a clean re-install to get it working again, unless there is a trick with a "Peferences" file somewhere.......