I'm going to guess that, while useful (especially for the Type keyboard), this method of putting the keyboard on backwards is "not operating under normal parameters." Theoretically MS wants you to just fold it back directly because that's faster than removing and flipping around, but the hybrids that do that with moving keys--doesn't feel right. I wonder if the 2nd gens will continue to expect this behavior too.
Yeah, it's not all the time for me, it's most at random. There are days when I have the cover backwards and the Start button doesn't work but only vibrates.....but then other days there's no affect and works just fine. So moments like this when the button is not working, I just do a right swipe and use the on screen start button.