The damn scroll ball works half the time. I sent the first one back for a replacement and now my second one is doing it too. I guess dirt gets inside there and messes it up. Cleaning it with a wet towel upside down is really only a quick fix and it is only a matter a days before it will act up again. Honestly I think Apple should recall these mice. IMO this is a defect. For me to stop what I am doing, take 10 minutes of of my work to clean the mouse and get totally off track is just not practical. I think Apple should implement something similar to the scroll wheel on the iPod on the mighty mouse instead of the ball.. I think that would be really awesome!