W-W, try this:
In develop, select an image in the filmstrip and in the Basic panel click on any slider name, e.g. Highlights. When you click on the slider you'll get a brief pop-up message to say "Modify Highlights with the +/- Keys"....so do that, i.e. use those +/- keys to make an adjustment to the Highlights.
Then, click on the next photo in the filmstrip (or use the right-arrow key), and then without clicking on any sliders simply use the + or - key. Which slider moves? On my Win7 system it'll be the Highlights, but the OP says on his (Mac) system it'll be the Exposure slider, which is not what he wants.
