Version:           4.7 (using KDE 4.7.0) 
OS:                Linux

When logging out of KDESC, it looks as if my computer was falling apart. Usually, the sequence is roughly as follows:

1. I click "Shutdown" on the Shutdown dialog
2. Nothing happens for some seconds (e.g., three)
3. Everything disappears besides one application (e.g., firefox): the desktop background vanishes, the panel vanishes, the window decorations disappear.
4. This sole application stays there for some more seconds (e.g., five)
5. Finally, the screen goes completely black, X is killed, and the TTY takes over shutting down

Reproducible: Always

Steps to Reproduce:
Shut down your computer from KDESC by any means: kickoff, the shutdown plasmoid, the desktop's context menu,... doesn't make any difference

Actual Results:  
My computer seems to fall apart

Expected Results:  
After clicking Shutdown, the screen is immediately blanked, so I don't notice all the gory details like shutting down kwin, terminating all the applications, ...