I just upgraded my 2.6 i7 16GB 1TB fusion drive Mac Mini to Yosemite and now the two displays (Dell monitor & Sanyo Projector) have switched roles. If I do not have the Apple Mini DisplayPort to VGA Adapter plugged in there is no problem. However, with it plugged in and the Dell monitor plugged in with the Apple Mini DisplayPort to VGA Adapter the primary screen is the projector no matter what I do. Got any suggestions or keystrokes that will get things the way they were with Mavericks? I use the Dell monitor as the primary with Keynote or PowerPoint or Pro-Presenter being displayed via the Sanyo projector.