Why do I need to auto-adjust my LCD monitor when switching between Windows and Linux with a KVM?

"The most likely reason is that your different machines are running at different resolutions or refresh rates. Even if they're identical, though, different video cards produce subtly different output (*), so your monitor needs to adjust for optimal performance.

(*) Matrox used to make a big deal about how their black-to-white pixel voltage spike was sharper and faster than other manufacturers. You could see the difference on screen, so it wasn't all hype."

You might could try a DVI KVM instead. I use this one in the setup you described, and I have no problems: http://www.newegg.com/Product/Product.aspx?Item=N82E16817399024