Since about a week I got a new monitor ( Samsung Syncmaster S24B350 ) and the first thing I noticed when I booted in my Windows(tm) partition was weird black borders around the desktop. Not being able to use “auto-adjustment” I scratched my head over this and went into the Catalyst settings. Here I noticed I could disable underscan and get this problem fixed for Windows(tm). The same problem occurred in Sabayon. The same solution applied using the /opt/bin/amdcccle tool but the settings were gone after a reboot. Obviously not using that gui tool right.. even as root I could not get it to save my settings.
To perm fix this, from a root shell run:
Hope it helps somebody.