as I have been seeing this problem is quite common. My LAPTOC have a monitor with a maximum resolution of 1600 * 900 and I bought a Samsung full hd monitor. When I extend the display, are clearly black edges.
I have a Dell (Intel I7 QM 2670) Windows 7.
The issue is that I was not to be the Catalyst Control Center. I looked in options and Intel Graphics Media (R), I tried several of the options described in this blog. For example: Maintain Display Scaling, customize ASPECT ratio, underscan (not included overscan option)
I'll have to get off drivers or what my problem is?