Problem with 1680 x 1050 resolution

I recently developed a problem where 1680 x 1050 resolution somehow has frequencies out of wack.  The screen appears about 3 inches ascue and I can't see anything that would abppear in the far right portion of the screen where the far left portion is blank and an error comes up that says the horizontal and vertical frequncies are our of range.  If I change to a different resolution everything is fine.  I tried updating my video card drivers and it says what I have is up to date.  What should I do?