Vista - Resolution disappeared

I had my res. set at 1440x900, turned my comp off. the next day i turn it
back on and the resolution was different...i went to turn it back to
1440x900(my monitors natural res) and its no longer even an option! i
have the choice of 1360x768, then 1600x1200. i attempted to system restore,
re-install my graphics driver, plug the monitor into my alt. output
on the video card, and ran safemode to see if the resolution was there. no
luck so far, any assistance is appreciated.

-darkphox