I've been having what seem to be fairly common problems with kernal panics and wake-from-sleep crashes since I installed a crucial 512 chip in my iBook 933. This morning I called apple and they recommended that I remove the chip, return it, and buy one of theirs. I asked if they knew of any compatibility problems with crucial and they said 'no'. I then called crucial; as soon as I mentioned the problems I was having the operator immediately recognized them. He says: 'Oh, yes, we know there's a problem with the chip we were sending out for that model (all ibooks or just 933? he wasn't clear). Send it back to us and we'll send you a revised version, and your problems will all clear up.' So we're doing an exchange at no charge. I bought the original crucial chip in late February. I thought other ibook owners might be interested in this...