So why don't you just use that then?
It is working as expected then; at 1920x1080 you get a x4 scale to 1280x960, which leaves 60 pixels on the top and bottom of the main screen. It's always preferable to let your graphics card do what it's good at rather than have allegro do it in software (and less good I might add) when it comes to mag filtering/fitting to a display/whatever.
It shouldn't be blue like that though. I'm still looking to see what's happening there...
