Window buttons stuck on right side

view story

http://askubuntu.com – After I upgraded to Quantal the window buttons of not maximized windows mysteriously moved to the right having the order they have in the panel when maximized. And I can't put them back to the left which is really annoying. I guess something was messed up during the upgrade. I tried Ubuntu Tweak and gconf-editor so far but changing the button layout there doesn't do anything. Any suggestions? (HowTos)