After running YUM system doesn't boot
I have been running FC4 for few weeks. Everything was working fine untill today when I ran yum check-update and then yum update. After updates were done, I restarted the system, and it goes upto SWAP FILE OK, and then freezes. I have used YUM in past for updates without any problems, I need to know how can I repair the installation or reverse the changes that YUM made.