trouble with f17->f18 update

[Neal Becker]

If you use --enablerepo=kde-unstable,kde-testing

on f17, expect trouble when updating to f18.

I used fedup, which didn't complain, but left with a system where kde wouldn't 
start.

You might want to use yum distro-sync before running fedup.

I don't have kde-unstable,kde-testing enabled by default in /etc/yum.repos.d.  
Perhaps if you do, fedup will use it and then you won't see this problem.