Mach needs an image there for the button to work correctly.
If you notice in "Simple screen" that the LED intermittently works, that is because I had no image for the buttons.
The work around is to load a transparent image.
You can create your own or use the one provide below.
Just drop that in you bitmap folder and load it for your invisible buttons that are over the "LED buttons".
Mach needs something for a place holder for them to work, that is why you have to use a"clear" image over the LED.
Also check that the button is ontop of the LED in Screen 4