1/3rd screen only visible after anniversary update

[ass17]

Hi all,

 

Is anyone else experiencing only 1/3 of the screen, then when you do something graphical or switch resolution it returns to full screen?

 

The machine is s dell 7440 with Intel 560 graphics, connected via hdmi to Epson projector.

 

I've updated graphics card drivers, changed refresh rates etc....

 

Didn't happen before update....