Detect Physics Rest (object sitting on object)

Well... how do you do it? :D

I want to destroy an object when an other sits on it for a while using the physics behavior.

But as it seems the collision isn't triggered anymore once the object "rests" on an other object :(

Here is my test .capx:

http://dl.dropbox.com/u/45711709/PhysicsRest.capx

Disable the 3rd event to see what i mean. I just use it as a workaround for now... but it's kinda crap cause it influences the physics object :(

if you make the collisionbox a bit smaller so that the image is a bit overlapping, it works

also something i noticed, with firefox and opengl activated, the framerate looks way too high, like its not capped..