The options menu doesn't block mouse events from going through to the menu below. This is apparent when you are in the hangar and open the 'Options' menu. Select 'Controls' to have a larger overlay. You are able to click 'Next' on the hangar-menu below, even though interaction with that button should be blocked from the overlay. You can even see the crosshair-style mouse pointer moving on the menu below. You should block out all interaction with the superimposed menu.