I've had good and bad upgrade experiences before, but this is killing me. My home machine is my domain server and it's been pretty badly crippled because of the mail problems. I can still use my palm but it's a new experience in being crippled.
I did a log of swearing of FC4 myself, when I was running into random bad behavior of various config tools. What happens when you boot with enforcing=0? That disables selinux. It cured all my problems. If that works, then selinux should be re-instated, with the right policies, etc.