I've got Kubuntu Vivid with all current upgrades, Nvidia 346 drivers. While usual work in thunderbird, system freezes for quite a long time (2-5 sec) and then I see notification that "effects was restarted due graphics restart". Reproducible: Always Steps to Reproduce: 1. Just regular work in Thunderbird 2. Sometimes it happends when I move some elements in window 3. Sometimes when selecting text. 4. After first effects restart Thunderbird and system become unusable, It continue to restart effects untill I kill Thunderbird. Actual Results: effect restart loop Expected Results: Smooth work
see bug #346116, notably comment #2
Works fine for me. If you're still able to reproduce the bug, please reopen the bug report.