Comment 2 for bug 1469449

I have exactly the same on my Ubuntu 14.04 Dell Precision M4700. It has an AMD card (see below), so it doesn't seem the problem is nvidia and/or driver specific.

$ lspci | grep -i vga
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Chelsea XT GL [FirePro M4000]

A few months ago, I switched between proprietary and opensource drivers, IIRC the problem wasn't there before the switch. I'm actually not sure what I have installed now; this is what dpkg tells me:

$ dpkg -l | grep -i '^ii.*fglrx'
ii fglrx-amdcccle-updates 2:15.201-0ubuntu0.14.04.1 amd64 Catalyst Control Center for the AMD graphics accelerators
ii fglrx-updates 2:15.201-0ubuntu0.14.04.1 amd64 Video driver for the AMD graphics accelerators
ii fglrx-updates-core 2:15.201-0ubuntu0.14.04.1 amd64 Minimal video driver for the AMD graphics accelerators