I got a Bluetooth Mighty Mouse in December '06 and haven't been using it much over the last week due to the batteries (2nd set) being low - am waiting for a charger to arrive. Today I decided to use it - however it seems to have stopped scrolling downwards - it'll scroll in every other direction but down. I've tried cleaning it (well, as best as I can do), but that just seems to have made it worse. What can I do to get my scrolling back? Downwards is my most-scrolled direction!!