I've used Apple Magic Mouse for more than a year with my MacBook Pro, and I notice that as time passes its tracking precision degrades. Last month I found myself with an intolerable jumpiness of the cursor. When I bought this mouse it worked on nearly every surface, now it works only on a piece of yellow cardboard I use as a mouse pad, it stopped working on other surfaces.
Of course I replaced/recharged the batteries, cleaned the laser lenses, and tried alternative surfaces. The Bluetooth radio has no interference since the scroll works perfectly, and the mouse is 10cm away from my MacBook.
Does anybody know why the performance of my mouse degrades? How do I fix it?