This is a bug in kwin from kdebase-workspace. It's fixed upstream in 4.2, but it doesn't seem to be backported to 4.1.x in KDE's or Kubuntu's packages.
** Bug watch added: KDE Bug Tracking System #152914 http://bugs.kde.org/show_bug.cgi?id=152914 ** Also affects: xorg-server via http://bugs.kde.org/show_bug.cgi?id=152914 Importance: Unknown Status: Unknown -- X freezes when reenabling compositing in kde-window-manager https://bugs.launchpad.net/bugs/249251 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs