Comment 22 for bug 175909

I'm using Kubuntu Gutsy, fully updated, and have had this problem since upgrading from Feisty.

One interesting workaround, though it does require gksudo, is to simply do: gksudo kcontrol. This generated the following konsole output:

$ gksudo kcontrol
kbuildsycoca running...
ing new authority file /root/.ICEauthority
DCOP Cleaning up dead connections.
kdecore (KProcess): WARNING: _attachPty() 12
QImage::smoothScale: Image is a null image
QImage::smoothScale: Image is a null image
QImage::smoothScale: Image is a null image
$

The 'cleaning up dead connections' part looks interesting.... After doing this, the root-owned dcopserver was gone, but more importantly, future use of kcontrol from the normal menus just works - e.g. on the Login Manager tool within Kcontrol, the Administrator Mode works (doesn't prompt as the sudo is established I guess.)

Not sure if I will need to re-do the gksudo invocation every time the sudo credentials run out, but since "gksudo kcontrol" could be put in the KDE menus it may be a better workaround than using Konsole. I would still really like to see a fix though.