My sins version say 1280x1024 but it is in reality 1680x1050... because i have mess up the file manually...
If you really wish the 1680x1050, simply go to your local folder... there with the savegame, mods, etc... you have a directory called "Setting"... in these directory, open with notepad the file called "user.setting"... and modify it to have something like show below :
VideoIsWindowed FALSE
VideoRefreshRate 60
VideoFullScreenWidth 1680
VideoFullScreenHeight 1050
VideoWindowedWidth 1680
VideoWindowedHeight 1050
VideoMultiSampleType 2
Be sure to type a refresh rate that your graphic card and your monitor can both support... the VideoMultiSampleType is the antiliasing level...