Can't reboot, shut down or log out.

[qwesto]

Hello,

I have an iBook G4 on which I can't log out the current user, nor reboot or shut down the computer. When I either use the keyboard shortcut, the pulldown menu or press the Power Button, nothing happens. CMD+CTRL+Power Button or 'sudo reboot' works to force a reboot.
I updated to Tiger today (10.4.2) from Panther (10.3.9), and the problem (which existed before the update) persists.
I have tried to log out/reboot/shut down from another user, it does not work. I've also flushed the cache and repaired disk permissions. Nothing has happened. So now I need help!

Thanks in advance!

--
Jimmy Lundgren

[hayne]

See this other thread with a similar problem:
http://forums.macosxhints.com/showthread.php?t=45857

Try doing a "Safe boot" to see if that makes a difference:
http://docs.info.apple.com/article.html?artnum=107392

Otherwise try the standard troubleshooting suggestions:
http://www.macosxhints.com/article.php?story=2004011205473937
http://forums.osxfaq.com/viewtopic.php?t=7269
http://www.thexlab.com/faqs/faqs.html