I have a workaround for this bug, although I'm unsure if Ubuntu has the
needed package for it since it came from the Arch Linux forums.
Anyway, instead of telling the GTK-QT-Engine to use the same as KDE,
download and install the Oxygen GTK theme and set it to that instead. It
kills this problem
Public bug reported:
Binary package hint: gtk-qt-engine
When running the gtk-qt-engine in KDE 4.2 (Beta 1) in Kubuntu Intrepid,
Firefox doesn't close properly. When I close Firefox, the process is
still running, so attempting to open it again gives me a Firefox is
already running error. I have
