I remember something like this in Windows so whatever it is seems to be a Microsoft problem. I saw that happen on my Windows laptop when I plugged in the projector and the laptop resized the display to match the projector. Lesson learned. Connect to the projector then launch the app.
If you feel Microsoft can fix this, call them.
<span id="INSERTION_MARKER"> Hi - I'm having an ongoing problem since I started using a Mac. What happens is I click the diagonal expand arrows at the top-right corner of the window<span>
and it expands the window and puts it in a new screen (as expected). However at some point during the day as I'm working, it changes and gets stuck in a not-quite-fullscreen purgatory. As you can see from the images below, the window moves from a separate screen to the main "desktop" screen, but it thinks that it's still in a separate screen.
.Additionally, as you can see it is no longer taking up the full screen, but the entire top bar (with the +, -, x and expand arrows) are no longer visible so I can't even re-expand it. The only way to fix the problem is to force quite the application and re-open.
<span>It seems to usually happen when I switch from main display -> external display (e.g. projector) -> main display but today it occurred without any display changes. Also, I can't recall whether it's happened with non-MS office related programs (e.g. Oultook, Excel, PPT), but those are what I mostly use. I'm using a MacBook Air w/ OS X v10.8.2. I'm using Office Mac 2011 (PowerPoint is v14.2.5).