it is as the subject says. I can't shutdown, via log out -> shutdown, my Pclos (Xfce) while compositing is activ. Reboot works fine. What happens: The System goes into a black Screen with a frozen cursor at the top of the screen. All i can do then is to shutdown forcefully via powerswitch. Has someone an idea what could fix that Problem because i would like to stay with my compositing activ.