LR 6.3 Mac osx: next light mode buggy in the develop module. When I go to the next light mode ("dim" or "off") and select a different step in the development history, the screen overlay will cover up the image (regardless of which overlay color I choose in preferences>interface>lights_out). So I can't any more compare development settings in both a dark and a light context. A major PITA when fine tuning lightness! Why, oh why, did I upgrade???