Descriptive Problem Summary:
Image overlays don't seem to obey the mouse_opacity of whatever they're attached to.
Numbered Steps to Reproduce Problem:
Create two objects in the same location.
Set the lower object's mouse_opacity to 1.
Set the higher object's mouse_opacity to 2.
Add an image overlay to the lower object with a layer higher than the higher object.
Click() the image overlay of the lower object which is displayed over the higher object.
The higher object should catch Click().
The lower object is catching Click().