I have a Magic Trackpad 1 that when I replace the batteries and i push the power button the green light comes on and the trackpad powers on. However, when I go to shut it off I hold the power button down and nothing happens. I can not get it to ever power off. Needless to say that if I don't remove the batteries I go through them every couple of days. Any ideas on how to resolve the trackpad not turning off? Thanks!