Hello all, (Note, these are G5 iMacs being talked about) Under my advice my friend got a 20" iMac (rev b) about 6 months ago. Everything was great until he bought a stick of RAM from me that was in my 17" iMac (rev a). Once my stick of ram was in, he got a kernel panic from time to time-- until the frequency of the KPs was unbearable. So we took my stick of RAM out of the iMac and he has his factory installed stick in there now. Everything has been running smoothly again, until he got his external firewire hard drive. Hooked it up, everything was fine. He started transferring 160 gigs over to the hdd, which naturally caused the fans to start up. About 80% of the way through, he got a Kernel Panic and was forced to restart. When he turned the iMac on again, the screen was on and all, but there were a bunch of pixels that were randomly turning white and then back to their original color. He has a black background, and it sort of looked like that Windows screen saver where stars fly by. Anyways, after another prompt restart, everything was fine again. He turned his new FW external on, and it did not show up. Disk utility does not find it at all, and it is nowhere to be found. He hooked it up via USB and voila -- it showed up just fine. Now we are at the point where we are both very confused and do not know where to go from this point. I told him to call Apple and return the iMac as it is still under warranty, and I feel really bad for him. Because you can't get an RMA number online, the website reccommended he take the 20" iMac to the store (about 10/15 miles away, but we don't have cars at school.) to get 'help'. Any advice would be more than welcome, kindof at a standstill on what to do.