CTRL breaking eventlisteners

I am making a game and there are eventlisteners on a timeline which are added and removed when they are not needed:

this.stage.addEventListener(KeyboardEvent.KEY_DOWN, Perfect);

this.stage.removeEventListener(KeyboardEvent.KEY_DOWN, Early);
this.stage.removeEventListener(KeyboardEvent.KEY_DOWN, Late);

Like that.

These eventlisteners are specifically looking for arrow keys to be pressed. When I press the control button, it breaks everything… and none of the eventlisteners work. It only breaks when I press the control key… all of the other keyboard keys do not make any difference.

Does anyone know why this is? Is there a way to disable CTRL key… or not listen for this specific key or something?