Had the same issue. I have a triple monitor setup with one main full-hd as the primary display connected via hdmi and two side monitors running 1280x1024 connected via DVI. My primary monitor only has HDMI so I'm not able to try using a DVI cable. I went to the nvidia control panel and just changed my primary display to be one of the smaller ones instead of the one connected via HDMI. This instantly fixed the problem and I can run any resolution in KSP. Hope this helps