Comment 10 for bug 1295267

Exactly the same issue here.

I've used Ubuntu for years with multiple multi-display setups (one at work, one or two at home). This did not used to be a problem. The first occurrences seemed to coincide with the time I bought a new monitor (and new model) that is 2560x1440. At the same time, I also changed one external monitor config to over-under rather than side-by-side.

Possibly related: In #1351982 (https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1351982), I described a problem in which the panel and indicator bars are occasionally unresponsive to mouse clicks after an unlock. Relocking (with ctrl-alt-L) and unlocking restores both reliably. The two bugs don't seem related functionally, but I think they did start occurring around the same time.