Native Resolution Not Selectable

Hell all,

im having a new issue, that only popped up recently, when i launch the game i am presented with the choice to pick resolution and windowed mode

my problem is, my native resolution of 1440x900 is no showing in the list of resolutions, anyone know how i can fix this?

i tried to look for the cfg file to add it there, but could not find it

any help is appreciated, thanks