Havent looked at the specific capx, but off the top of my head here's a few things....
System / On start of layout / Sprite / Start animation from beginning / current frame.
is the correct usage for starting an animation.
When it asks you in the dialog box to specify which animation by name make sure you spell it the exact same way as you named the animation when you were adding the frames to the sprite. and it should have "quotes" around it.
Next. Click the animation name in the list of animations with the sprite sheet open and in the properties box in the upper left, make sure speed is set to something like 15
Also make sure "looping" is set to YES
also, each frame of the animation click it and set its own "frame speed" to something greater than 0 if its not already.