Problem narrowed down: the culprit is {kdelibs kdelibs-bin kdelibs-data kdelibs4} version 3.1.4-3.
Downgrading to 3.1.4-2 fixes the problem.
I'm having similar problems, opened synaptic to discover I have 3.1.4-3 installed, but how do i downgrade? I only know how to upgrade, I don't think synaptic has a downgrade option...
Thanx, David