AS 3 Disable MOUSE_OVER for Button instance

That time again folks that time :

How do you disable only the MOUSE_OVER event for a an instance of the Button class in AS 3?

MyButton.Mouse_OVER = null ;
Will not work as it is not a writable property.

MyButton.enabled = false
Will not work as that disables the entire Button and that is not what I want.

Any clues, willing to trade meth lab for an answer to this one…

Peaze Dylan