I hadn't ever tried the 1/2 and 1/3 display before, thanks! But I'm still getting black boxes on the geoscape no matter what I do, and it seems to be because Windows or my screen doesn't properly support the 16:10 aspect ratio. If I set it to a 16:10 resolution, I might get black boxes (sometimes very large) which don't show on screenshots accompanying a highly distorted image which only looks fine in screenshots, or I might get standard black boxes and when I check the resolution, it isn't what I entered in the box.
I am also unable to reach 1920x1200 resolution. I guess it is too high for my hardware or software? If I set 1920x1200 the game puts me at 640x480. 1920x1080 is so close, but 1920x1200 would be perfect because it's 6x the original, making a perfect match for both 1/2 and 1/3 display.