I've just installed Kubuntu 11.10 - and it looks like some gnome lib is missing - selectors like that:
doesn't work: I can not choose with a mouse tabs on the left. I've installed gnome-common but it gave no help.
It seems like its a theme issue, try:
I don't use KDE but I've seen a lot of problems with the KDE themes on 11.10
The problem is resolved by installing