Button to fire the script doesn't yield the same results as firing a script via its clock

To be specific I am going through the Calder's mobiles example from Learning with Etoys http://archive.flossmanuals.net/learning-with-etoys-imagine-invent-inspire/calder-mobiles

I've set up everything and the toy behaving differently depending if I fire up the motion script via its button or via its clock.

It works fine when I fire up the script via its clock. When the mouse is over the mobile it shrinks and when the mouse is not over the mobile it grows.

However, when I fire it up via its button the mobile starts to grow and mouse-overing to shrink doesn't work.

My motion script looks like this:

Test mobile's is under mouse:
    YES:
        mobile start script shrink
        mobile pause script grow
    NO:
        mobile start script grow
        mobile pause script shrink

Thanks,
Larper