yum upgrade breaks centos 4?

Is there some packages I need to exclude on a yum upgrade for centos 4 aside from the kernel ones? I recently tried to upgrade my linode running centos 4 after a clean deploy of it and it broke it horribly. weird errors on the screen whenever i typed any command at all. unfortunately I wasn't smart enough at the time to record what the errors were, and just redeployed centos since i was on a crunch for time.

does anybody know of any packages that should be excluded on an upgrade?

thanks