iBook switches off

Hi everyone!

This evening my iBook started to do something interesting:

When I remove the AC adapter, it just loses power after a second or two... *zap* and it's off.

It won't start either.
If I plug-in again, it'll start without problems and even shows that the battery is fully charged...

Unplugged again, and *zap* it turns off after about 20 seconds...

???

Any ideas? I just repaired permissions and ran crons?

Going to try resetting PRAM next...

HELP!

I think I heard about this before, but can't find any threads on it...

Ok I reset the power management system and it seems to have fixed it.

Here's how you do it for reference:

Reboot, before you see apple logo press:
Shift-command-option-power key simultaneously and release.

Then the 'book will reboot and all should be good.