This problem started to happen to me not too long ago. When I quit Safari it comes up that it has quit unexpectedly and what would I like to do, reopen bla bla bla.

When this started to happen I was thinking about wiping my hard drive anyways and re-building the system and this problem sort of pushed me a bit to do that.

When I re-built the system the problem went away as expected. But now it's started again. It especially happens when I'm on youtube or watching video or looking a big files that take a while to open.

It also seems to happen when my fan is on and making A LOT of noise like a bee is trapped in my Mac.

Any ideas?

Oh I'm using a PowerMac G4 incase that helps.