[Display & Nvidia] Setting up Custom Low WideScreen Resolutions

I've recently purchased a Samsung Syncmaster 226bw 22". The native widescreen resolution (1680 * 1050) is obviously the best resolution to use. Unfortunately many games play much better at 75hz and therefore i prefer to use a lower resolution. The game I mostly play is Counterstrike Source, which supports widescreen modes.

Now the only widescreen resolution supported by windows and CSS is the native one, 1680 * 1050. I'd like to use a lower resolution that keeps the 16:10 aspect ratio. Is there any way i could create a custom resolution that's low but that also keeps the 16:10 aspect ratio, such as 768 * 480 or 800 * 500? This way i could keep a 75hz refresh rate and still play widescreen.

My gfx card is a 8800 GTS.

Thanks for any help

If I am not mistaken, most all lcd's, including Samsung, operate at 60hz. Don't worry, though, unlike crt monitors, there is no flickering image problem at 60hz, because the display is not always regenerated. Use the native resolution for best results if you can.

Okay i managed to use nvidia's custom resolution to create a custom one, but are there any drawbacks to using this? If it works alright does that mean its safe?

I thought increasing the refresh on an LCD screen from it's factory 60Hz to any higher actually caused damage to the screen? I could be wrong, but I believe I read it from someone here that has credibility (Can't remember who), oh well, Screens are not my forte, but one thing I know is that it's horrible to lower your resolution on LCDs as far as quality is concerned.