Further Information: The screen looked fine when using "try Ubuntu" from the install ISO.
I am running to a 1900x1200 external monitor via HDMI through an nvidia gtx 670 graphics card. I initially did not install any proprietary drivers, but installed nvidia-current after initially encountering this problem.
The screen appears to be offset to the top left, about 1-2 inches left and 0.5 inches up, so I cannot see the bar at the top, or the unity bar on the left. The screen also seems to be slightly distorted (window controls are horizontal ovals, not round). There is a black bar at the bottom / right of the screen.
If I adjust monitor settings to use "original" vs "full" display, I the distortion becomes vertically distorted, and I still have black bars / offset problems.