i made a video which is selfexplanatory https://dl.dropboxusercontent.com/u/1828618/displayfusionbug.mp4

I had the same problem as well. It effected my Start Menu and most app windows. I uninstalled 7.11 and re-installed it but just the same. I have now uninstalled it and gone back to 6.1.12 and all is well again.

indeed. just reinstalling 6.12 did the trick. glad its not only me

7.12 has fixed the problem, thanks Keith!