Since I went spelunking a bit, I shall leave some links - which may or not be related - for those who wish to investigate this further: https://bugs.freedesktop.org/show_bug.cgi?id=43760 https://bugs.freedesktop.org/show_bug.cgi?id=10693 https://bugs.freedesktop.org/show_bug.cgi?id=44624 https://bugs.freedesktop.org/show_bug.cgi?id=96893 https://bugs.freedesktop.org/show_bug.cgi?id=9029 https://bugs.freedesktop.org/show_bug.cgi?id=7223