I've been running FC4 for several months now and have been using yum update without problems. The system has been automatically selecting kernels with names ending in "smp". This morning, for no apparent reason, I kept getting a kernel panic when I tried to boot and the system hung repeatedly. I was only able to get past this by selecting 2.6.14.1.1644_FC4 instead of 2.6.14.1.1644_FC4smp from the boot configuration menu. It was just a guess. I have no idea why this worked. According to webopedia.com, SMP is "Short for Symmetric Multiprocessing, a computer architecture that provides fast performance by making multiple CPUs available to complete individual process simultaneously. Unlike asymmetrical processing, any idle processor can be assigned any task, and additional CPUs can be added to improve performance and handle increased loads." Does this refer to other processors on the same computer or on different machines on a network? The other machines on this very minimally networked LAN (just for ssh) aren't always up or running FC4 when they are up. None of these computers are dual core. I'm not trying to do any smp-type processing at this time. Could the smp kernel ran into some sort of synchronization problem with the other machines and now be "parametrically confused" about something? I'd like to either (1) reset it or (2) fix the update process so that the default is for non-smp kernels. Thanks for any suggestions.