Hi guys, I've just encountered a strange new issue on ML. When I switch between spaces via Mission Control, the app window that I switch to appears to be normal and 'in focus' for a second before it goes into 'background mode' and the traffic light buttons grey out, requiring me to click on the window to make it the active app again. This obviously gets annoying pretty quickly. I haven't noticed this happening before, and I've already restarted my MBP just to see if it helps, no solution yet. Any help please?