I have an EliteBook 8570p in a docking station, with an external monitor and keyboard attached.
I typically have my display mode as "duplicate", with the same thing showing on both my laptop screen and external monitor. I use the external monitor as the main screen. This might be uncommon, but I prefer it this way. I've been working this way for quite a while.
I very recently started using MS PowerPoint 2013. Today I discovered an annoying bug (feature?) with this combination. I was in "slideshow mode" for a pptx I was working on, and I pressed ESC to get back to editing the doc. What happened was that the external monitor just showed my background wallpaper, and the laptop screen showed the normal display, along with my background wallpaper. I then had to slide over to my laptop keyboard and press Fn-F4 and set it to "Duplicate", and that restored my external monitor display.
I don't like this behavior. I also noticed that when I go into slideshow mode, the display on the laptop screen is different from what I see on the external monitor. It looks like it's showing an "intelligent" view of the slideshow, with a big panel showing the current page, and the next page in a smaller panel. That's interesting, but I don't want it to do that if I'm in "Duplicate" display mode.
Is there a way to get the "older" behavior from PowerPoint 2013?