We fixed it!!!
So: the overscan is fixed in the settings of the bravia tv itself. In order for the full pixel mode to show up at all we had to adjust the tv settings *while it was playing a video*. We went into windows media player and had a vid play on repeat. It gave me time to dig...
i have the GeForce GTX 550 TI and the same exact problem. This is the most frustrating thing ever - but you're not alone!
Edit: For what it's worth, I'm using a new ibuypower hooked to a sony bravia tv via hdmi with windows 7 64 bit. The screen will flash to black for a moment (during which...