problem with splinter cell 4 (i've already read the last..

[maphisto324]

important notice: i've searched and read the last threads on this game.

I have a 2007WFP and can't get the game to work at 1680x1050.
i've tried this solution:

In SplinterCell4.ini (in both online and offine folders)

FullscreenViewportX=1680
FullscreenViewportY=1050

but when I change the full screen res from 1280x1024 to 1680x1050, the game do an error right after he comes up.

those who succeeded to run this res, u've just changed the ini and thats it?

also, why does it happen? when I had my crt, in the display option i had allot of resolutions- 5:4, 16:10 ect'. what in IUO is the reason that when we plug in an lcd, the resolution disappear?