Comment 13 for bug 1631519

I managed to reproduce it once trying to move from the on-laptop miniDP connector to the dock's full-size DP connector -- then I had a black background (well, no backgound) and the window trails.

It looks to me like an issue in compiz, but it might really be X. In doubt, I'm not going to change this and let someone more knowledgeable than me investigate this further.

If anything needs to be attempted, my X230 doesn't ever run anything important (I use it for running installer tests, etc.), so I can do further testing (and reinstalls).