Windows 7 Nvidia Can't Create custom resolution

[Doomofman]

I have an HP and for some reason my monitor has a strange tendancy to not be detected... Thus stopping me from running 1680 x 1050 resolution... In Vista I could fix that by creating a custom resolution with the Nvidia control panel... But on Win7 When I click apply for 1680x1050 resolution the screen flickers twice and goes back to 1600x1200... Anyone any ideas how to stop it acting up? I really need the proper 1680x1050 resolution