resizing/movement of windows impossible

Hi everybody, I am running a SuSE 9.1 desktop machine. My machine worked well for months now, but currently I am unable to move or resize *any* of my windows (only minimize and maximize and close buttons work). It does not make any difference, if it is SuSEs yast window or any of my xterm windows. (all of them opened on a KDE WM). Hope that someone can help me here - it is horrible! Martin