Hello,
I ve got to say that i have the same problem with my W7 Pro.
My LCD is connected to HD3200 (IGP) via HDMI native resolution of display 1920x1080 but there is boarder!
I've instaled newest bios, GPU drivers, Updates from windows but nothing helped.
What's funny on second HDD i've got seven ultimate but RC version running without any problems with the same driver set!
I have studied lots of forums but no help at all :/
And tech support on microsoft site is out of order :/ HELP !