unless you have some reason not too, you should always shoot for the lcd's native resolution and refresh rate(which is probably what the error message is telling you, 1920x1200 60hz) on your emulators and even in windows. for the most part, as long as you don't turn on any weird filters, things will work out best that way. of course not all older emulators have settings for newer resolutions, so that may be causing a problem too. try to change all resolutions to the monitors actual pixel count and see what happens.