Comment 34 for bug 297143

Interesting that this bug is still marked as unconfirmed. I can clearly see it myself on my laptop running Ubuntu 14.04. It's not that clear to me yet when it directly starts but it might have something to do with hibernation. When it occurs the CPU load of Xorg and compiz is raising up to 60% and stays at this level until the application gets closed. In my case it is mostly Thunderbird.

I have updated to Ubuntu 14.10 now, and will closely watch this problem over the next couple of days to maybe find a pattern to reproduce.