Somehow I tried to run chromium as root last night and now chromium
brings up a window, but with the window only showing the existing
background and not actually doing anything.
see: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=793748
It is also difficult to quit chromium except by a kill -9 of the main
process.
A clue appeared when I was unable to run vlc (which uses vdpau by
default) or mpv (which uses opengl by default), getting the same
unresponsive windows.
Once I moved the vdpau libraries out of the way, mplayer ran ok using vx
and vlc ran ok (using xv?).
Where would I look for what was broken and what files might need to be
reinstalled?
KDE is mostly at 4:4.14-2-5 here.
I'm happy to supply any more information on request.