My iBook has been getting progressively worse with its kernel panics, sometimes requiring up to eight reboots in order to be working correctly. Sometimes, I'd end up with a blank screen and have to hit the power button just to reboot.
In a previous post, I mentioned that after pre-heating, the iBook ran pretty stable. So now, it's on ALL THE TIME. I'm not shutting down or closing the lid. I've set the energy prefs to shut off the screen and hard drive, but I'm never letting it sleep.
So far, so good... 100% uptime for about three days.
UPDATE: Still 100% uptime. And, I'm running this, so the cycles aren't wasted.