This turns out to be a mesa bug. I built a test package with the mesa from the upstream mesa bug referenced in the linked KDE bug:
KDE: http://bugs.kde.org/show_bug.cgi?id=241402 Mesa: https://bugs.freedesktop.org/show_bug.cgi?id=30220 I'll attach a debdiff in a bit. ** Bug watch added: freedesktop.org Bugzilla #30220 http://bugs.freedesktop.org/show_bug.cgi?id=30220 ** Package changed: kdebase-workspace (Ubuntu) => mesa (Ubuntu) ** Also affects: mesa (Ubuntu Maverick) Importance: High Status: Confirmed ** Also affects: mesa via http://bugs.freedesktop.org/show_bug.cgi?id=30220 Importance: Unknown Status: Unknown -- Display freeze when changing kwin effects settings if effects are active https://bugs.launchpad.net/bugs/633406 You received this bug notification because you are a member of Ubuntu-X, which is subscribed to mesa in ubuntu. _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp