Your monitor perhaps identifies itself as a TV, or the driver software
makes a bad assumption on seeing a 1080p device. I've had trouble with
getting 1:1 pixel correspondance on TV-like screens before, too -
though not with Windows. Overscan/underscan is an unnecessary
irritation on non-SD screens.
Cheers - Jaimie
--
"The polar opposite of cinnamon is frogs." -- Mandy, in "Mandy the Merciless"