be sure to update the thread and let us know if it worked. that way, others that have the issue will get good search results (at least, when they search)
if it was for all users, i'd try abandoning the nvidia drivers altogether and force vesa, by uninstalling all drivers and reconfiguring x (or mod'ing xorg.conf)...just to see if it worked.
since it is just one user (root), it sounds more like your kde settings are hosed. perhaps if you renamed ~/.kde, .kde3, .kderc and then restarted X you might get a clean slate?
just a thought...good luck with that.




