Two ideas. 1- Replace your clock battery, especially if you've had this machine for a few years. 2- Remove any recently-installed memory chips, leaving just the stock Apple memory in place.

I doubt this is due to a virus. There has not been one single virus infection verified in Mac OS X ... I emphasize the _operating system_ which you say is crashing. Now there are all sorts of Micro$oft email and Word macro viruses, but they don't crash Mac OS X, the system.

My G4 with OS X would freeze unexpectedly, until I removed a bad memory stick/board that I had added on. Now it never freezes.

This is a kernel panic.

As noted above, RAM can be a culprit. Particularly if you recently updated to a new version of the OS from a previous one that 'worked fine'. Newer version of the OS can tax RAM more, and can expose previously hidden bad componants.

It could also be related to other items of hardware. Some peripherals you have plugged in perhaps.

It could also be related to some software you've installed. Perhaps it installed a kernel extention (.kext) that is poorly written/implemented or is incompatible with the last OS update/your OS upgrade.

They are tough to nail down. Try looking at /Library/Logs/panic.log (if it exists) for clues on what the culprit could be.

Also, here's Apple's suggestions for dealing kernel panics.

http://docs.info.apple.com/article.html?artnum=106227

P.S., definitely replace your internal battery.

Thanks so much! It makes sense. I will give both of
these ideas a try.

Thank you! I will replace the clock.

If it was upgrades that caused problems does that mean I should not download upgrades when they become available?

No.. we should simply investigate the cause of the problem and try to rectify them. Not upgrading/updating is not a good option. Most often these upgrades/updates contain imperative security patches.

I happened upon this thread via Google.. seems to be a great forum!
I have a similar situation with a G4.. every time I try to put an extra 512MB memory card into the last slot .. the machine crashes (kernel panic) without fail after a little while. (This might happen when memory is accessed/retrieved in the new RAM card)... I've used two different makes of card.. I'd just like to ask if anyone knows of a dependable make of card or if it's even worthwhile trying to put the max RAM in the G4....(733 MHz) ie can it handle three cards together at all?
Thanks!

Thanks to you, my original problem is fixed! Replacing the clock
battery stopped the daily crashes.

I know this is serious Necro-Posting, but I have been running into this problem a lot lately. Today I did some serious tests on it. Ran memory tests with a single 512 stick in any slot, and memory tests pass. When I insert another 512 stick into any slot, it failes, even when the same stick is put in by itself, it passes. We have tried the reset-nvram, and taking it back to the apple store. We have not yet tried to replace the battery in it yet. Thats next.

The crashes are very random, its not like a certain application causes these problems. Any Advice? I already purchased "MAC Certified" RAM.

It may have been a long time but I am still suffering from daily crashes. The battery solution did not help. I have one more clue and it may not be of any help but most of the crashes happen when I scroll.
I was planning to take out RAM and switch it around to see if some of it was bad but I am a application girl not into the hardware. I am afraid I will damage something.

xjoy@shaw.ca