Hey, I'm in front of my TV and notice I have about a 1cm black border all around the picture with the settings - do you have the same on your TV? How big is your TV?
ok so you have black border on desktop, load a 1:1 mapping image (tiger dave 1920 x 1080 test pattern) - fullscreen preview, tell me if you have 1:1 on desktop. If so then that black border is not part of the desktop, that is just the edge of the monitor.
to tell the difference between 1:1 and almost 1:1 you need to view at 90% and 100% and notice the difference.
Tried Tiger Dave's test pattern as suggested and it looks like I have 1:1 on the desktop. The desktop or the blue screen on MP startup fills the largest amount of the screen when compared to some broadcasts and this leaves about a 1cm black border. Really on my 52 inch TV, it is not a problem, but it would be nice to totally fill it if possible - it's really not a biggie. The main thing is the blurry picture has decreased to almost nothing.
If the desktop fulls the screen, but the broadcast leaves a black border, then the black border is from the broadcast
possible solutions are
1. leave things be <- which i recommend)
2. right click, select crop, crop out the black area
3. enable auto croper in MP Config (resource intensive)