I got around 50 FPS running the benchmark at 5040x1050 AA 4x .
4:3 = 1024x768
16:9 = 1280x720
48:10 = 5040x1050
If you try to launch it at 5040x1050 using the DX10 executable, it automatically switches to 3840x1024, and runs fine.
Some screenshots at 5040x1050 DX9 (click to enlarge):






