I'm using my iBook G4 and it keeps freezing on me. When I say freezing the arrow to click on a link won't move (this happens when surfing the net). I try to type something and it's slow to respond. It's hard to explain but it's froze up on me at least 6 times in 40 minutes. I recently had more RAM installed 512mb. I'd like help in solving this freezing problem. Please help. Thanks in advance.