I have noticed that on the latest version of Raspbian there is a white bar at the top to the desk top. I can put my mouse into this bar but I can't put any window into it. Sometimes the window is so large I get its top bar in the white bar and then I can't move it at all.
I know all about over scan and under scan and it is not that which is the problem.
Anyone know some config magic to convert it to usable window. It never used to be like this.