Sometimes the thumbnail is not erased when the pointer leaves the selector. Here is an example, captured with the pointer outside:
https://dl.dropboxusercontent.com/u/109232477/PixInsight/thumbnail.pngA bit hard to reproduce, it might take 10 or 20 quick repetitions before it happens: Hover to get thumbnail, left press, quickly move the pointer left or right (staying within the selector) so that both the view menu and thumbnail appear simultaneously. Move the pointer outside the selector. Press escape key to close menu. Thumbnail remains. Repeat this hover/press/move action quickly until the problem appears.
Also, sometimes thumbnail is repositioned to the center of the screen and back with small pointer movements (to avoid right hand screen edge clipping?). A bit annoying flicker, but minor.
Mike
