Actually most Samsung displays have a scale-down feature in them that allows the user to run higher resolutions in some cases up to 1920x1080 on a 1366x768 monitor. I know mine has that feature, and I have a 32" Samsung LCD TV.
Samsung TVs generally have a much more limited range of supported resolutions than LCD monitors (because they are televisions first and foremost, and therefore don't need to support a wide range of resolutions). Some resolutions that work on my TV are:
1280x1024 (I think)
Try some of these and see if it works.