For the passed few days I've noticed that fullscreen'd youtube videos and video games have black borders on the top and bottom of them but I had no idea what the problem was since my monitor resolution was the same as it had always been.
It wasn't until I launched the Steam 'big picture mode' that I saw what was happening:

You can also see the black bars I'm talking about in that screenshot.
I've absolutely no idea how to fix it so any help would be greatly appreciated. Tried updating my graphics card drivers.
