I have a issue with the mouse (wireless) working with my macbook pro, if it is hooked up to the external keyboard, or the macbook pro while the system is being charged, the mouse will work. But taking it to the library and wireless unit is hooked to the macbook it will not work? Batteries in the wireless mouse are brand new, and MBP is fully charged. Yes I can use the track pad, but I do not understand why the mouse will not work wirelessly unless the system is hooked up electricaly and not running on battery power. Any ideas?