Linux ATI Underscan Issue

I've recently installed Debian onto my PC and ran into the same problem I had with Ubuntu, and had to spend a long while finding the fix to it. I actually also had this problem with the same drivers on Windows 7 but the Catalyst Control Center GUI makes finding the answer a lot easier.

Here's the problem:

Images of problems thanks to am7146 of ubuntuforums [source]

The problem was due to the default setting of the ATI drivers setting the underscan to 20%. Why they would do this, I have no idea.

The solution is (as you'd expect) to change some of the settings! But which settings? Not the ones on the thread with the problem images!

I found the answer on askubuntu, here.

aticonfig --set-pcs-val=MCIL,DigitalHDTVDefaultUnderscan,0

Now if I ever decide to reinstall Linux on this box again I have the solution handy.