The panel (in KDE 4.1.3) must be clicked at least twice nearly every time to get a response, sometimes three times.
It is set to autohide. It seems to want me to draw focus to it with the first click and then the second is registered for a window activation. I know, because I will open a File manager window, click on a file in it and then click on the KDE panel below, but nothing will happen from the icon I click. I have to click a second time. If my mouse moves away from over the panel between the two click I have to click a third time.