Drivers for 1440 X 900

Using a Dell Latitude D800 (WinXP Pro) with a nVidia GeForce FX Go52000 graphics card and a newly added ViewSonic 19" monitor. Trying to get the resolution to 1440 X 900 and currently the best I can get is 1280 X 800. I have updated the nVidia and Bios drivers.

 

Any suggestions would be appreciated.

Thanks