Set your windows driver to NOT hide display resolutions your monitor can't show...
Once I saw this I had to try it, however I have no idea where to find the setting to allow the 1280x512 on the second display.

I'm running two 17"

Any assistance with getting the configuration in the image with the primary toon on display 1 and it split into two 1280x512's on the second display seamless would be very welcome.

Thank you!