I have a G5 dual core machine that gives me a kernel panic almost daily after I loaded Leopard. I loaded leopard (10.5.3) fresh to a new disk and I have had problems every since. Apple support has not been any help to me and in fact their support has definitely gone down hill but that is another story. I have tried almost everything, and that includes fixing permissions. But the problem remains. It seems to be related to Safari when it is playing a video. Many times the kernel panic occurs during or shortly after I play videos through Safari. Does anybody have any ideas what might need to be done?