I can't play windowed at desktop resolution, because winSP doesn'T know how to handle to desktops with different resolutions in this case.
But, yes, 1680x1050 is native, for monitor and video card. Speaking of:
GeForce GTS 450
Drivers 275.33
Dedicated V-RAM 1 GB
And I can't even select something other than GDI for fullscreen?
I didn't notice any distortions on my quick look, but the only windowed resolution that works (due to the 2 monitor setup) is some odd 1124 something.