One of my users recently received a MBP 15" Retina display. When connecting to a projector we figured out that he can only use the projector in 1080i mode(no signal otherwise). When using PowerPoint in presenter mode, he then loses signal to the projector. Setting the slideshow to fullscreen+mirrored it displays just fine. However, we also noted that he cannot advance slides when in full screen mode.
Auxilery info: I noticed a similar bug in Lion when using a powerpoint in fullscreen mode, a user was not able to advance slides. This is a 13" MBP running 10.7.4.

All office and Apple updates have been done.