When running a Slide Show on Mirror Show in OS X 10.8 Mountain Lion, the secondary monitor's display is too large for the screen and hangs off the side of the display. Running the same presentation from the PowerPoint Slide Show does not result in this issue. This issue does not occur on OS X 10.6.
The issue has been reported as an Office issue to Microsoft. Currently, there are three workarounds:
- Run the Slide Show in PresenterView. Refer to this Microsoft Office KB article for help with using PresenterView.
- Set up the Slide Show to Run from Kiosk in the PowerPoint Slide Show Options. Refer to this Microsoft Office KB article for help with using the Kiosk function.
- Mirror the computer displays and do not rely on PowerPoint's mirrored option. Refer to this Apple KB article for help on mirroring your display.