iOS Mouse events with buttons in Flash Professional

I have 2 images that I have conversted to buttons and exported to actionscript.

I have placed one object on the screen.

When I "roll_over", I want it to change to the other image so people know they are on the button.

When released, I have a "MOUSE_UP" event to trigger a function.

The problem is if I just use the regular Flash Proffessional "Up, Over, Down & Hit" that I get when I double click on a button, it does not change if I touch the screen and then move over to the object while still touching the screen.

I can do it in code and trap the evens, but I do not know how to change the pictures.

Does anyone have any ideas?

Here is my test file.

Thanks, Patrick