Hibernate button is there in Kubuntu 13.04 but confirmation button outside desktop

view story

http://www.kubuntuforums.net – Dear all I have installed Kubuntu 13.04 on a XPS13 (Dell). The hibernate button is there in the panel, so that's good. However when I click on the hibernate button (in the panel) it launches a confirmation widget "Do you want to suspend to disk (hibernate)" and only the upper part of the widget is visible, the rest (I guess the Yes or No buttons) lies below the bottom of my screen/desktop so that it is not accessible (and no chance to move it). (Best would be to show you a snapshot of the screen, but hard to do since I cannot access ksnapshot when the confirmation widget is on (HowTos)