I am using PPT 2013 on a Lenovo Ultrabook. When I create my presentations, my slides progress normally, set up to advance on click. However, when I hook up to a projector, they begin to advance on their own, they go backward, skip forward several slides, go back again - like it is possessed. Last week, I even took it off slide show mode, and the pages continued to move back and forth on their own while connected to the projector. As soon as I removed the projector connection, everything was fine. This has happened at least four times, using three different projectors. What's up?