When running Dishonored in windowed mode it does not use the full selected resolution - e.g. when I select 1920x1200 (which is also my native resolution) the window does not span the full width of my screen. Since I usually use GameCompanion to convert full-size windows to fake fullscreen (like in WoW etc.) this is annoying as it doesn't work - most likely due to the fact that the window is too small.
So I wonder if there's a way (such as an INI tweak) to make the game window use the full resolution I selected in the options.