This one time the time wouldn't keep on my ibook and everytime i turned it off the clock reset itself. Whenever i unplugged it and left the battery out.
I phoned apple and they told me to reset the power management thing while rebooting, anyway it didn't work. I went through some other steps with them and nothing seemed to work.
I had to send it in and it took about 2 weeks to ship it and get it back (i live in the UK).
At the time i had a broken modem connector where the cord was pulled from the machine and took the port out with it. They fixed that and i didn't mention it, the broken peices were tiny as well. So that was good
Anyway it still didn't work (clock reseting itself that is). I phoned them up and had it sent back and then 2 weeks later it was back in my hands.
IT still didn't work. i rang up the 3rd party that were holding my laptop, and I explained TO THEM (not apple this time) what i was doing and why the clock wasn't keeping the time.
Anyway, they mentioned the little known fact about the iBook not having an onboard cmos type battery ... yeah and how you've got to have the power cord plugged in or the battery in the machine...
Thankfully nothing has ever REALLY gone wrong.