Barry Yu, I got the same last night, it looks like a bug of the update, I download the kernel-doc-2.6.6-1.427noarch.rpm and manually installed it (rpm -ivh kernel-doc-2.6.6-1.427noarch.rpm), finally everything is back to normal. You can download it from : limestone.uoregon.edu/fedora/updates/2/i386 Good luck. Your solution worked perfectly. Thank you. Dwaine