Quote Originally Posted by rusty
Try also setting in /etc/kde3/kdm/kdmrc AllowRootLogin=false to true.
Did that and while root doesn't show up on the user list, I can log in by typing root and the password and get an x session going.
Same file a bit further down there's a line: HiddenUsers=root , remove the obvious or change the line ShowUsers=NotHidden to hmm, might be All but I haven't tested.

BTW, I never dist-upgrade. IMHO it's asking for trouble. Nevertheless, kelmo's method is probably the safest when it comes to KDM/E.