Chosen Solution
Since a few days the mouse is acting weird. When it is not moving the connection will disappear, when the mouse is being moved again it will connect again. Everytime you want to use the mouse it takes a few seconds before it is connected again. Even when you pause 2 secondes to decide where to click on it will loose its connection! This behavior is the same on different MacBooks and Imacs.
Try cleaning both the contacts in the mouse and the batteries. Look for leakage from the batteries. Use a slightly damp cotton swab (Q-Tip) with White Vinigar. Also try a fresh set of batteries. Is it any better?
