I had kernel panics with my iBook G4, but i was still running 10.3.9. and I did also have them when i tried to install 10.4 thinking it would solve the problem. Are you insured? because i took mine to the Apple store and got a genius to diagnose it and write up a report which i sent to my insurer with the laptop and they replaced the logic board, if you're not though, the genius said it costs about the same as getting a new computer to replace