Oh now i get it, it must be the only 720 vertical pixels that won't allow apps to run on a 720p screen.
This is from Microsoft itself:
It didn't work because it says "YOUR RESOLUTION IS NOT HIGH ENOUGH FOR METRO APPS" except you tweak the registry and then they suddenly work perfectly, which is why it's a bit of a ridiculous requirement.
" Windows Store apps require a screen resolution of 1024x768 or higher to run"
The problem is without a doubt on your side, 720p must be supported as far as i know and i've read all around the net.
and a reply from an MS tech guy from someone asking why apps won't open at 720p
The 1024x768 is a hard coded requirement for displaying the Windows 8 Apps.
So no, it's not on my end.
Your 1280 horizontal resolution is OK, but the 720 vertical resolution will not work.
Too bad for you man !