Okay, been busy these two days. I just checked out your code. You use two tween that plays together.
There are two tween which is Up, and Down; The problem is, the Up progress is still at 1.0 when Down finished playing, so Up won't be able to play since it's already at the end. You need to either use Reverse, or 'Seek 0' to place it back at the beginning.
This is the corrected capx and the other one is just something i think would simplify it. https://dl.dropboxusercontent.com/u/553 ... waves.capx https://dl.dropboxusercontent.com/u/553 ... aves2.capx
PS: I changed the tween behaviour a bit to help with reversing control, please redownload it.