Several games will " default " the display properties to the format they like ( highly unlikely to be the format YOU like, however ).
As per the good previous advice, ensure you "apply" the desktop properties to the required values. Has happened to me several times and can be a pain in that the "default" display actually pushes the apply button off screen !! Most annoying !!
Good luck and don't let this critter beat you - after all - you are an Aviator !!