Howsit guys

I'm doing a Angry Birds clone, it's coming together quite nicely however I've encountered a problem.

As many of you know a typical Angry Birds level starts out with 3 different types of birds all of which are fired through a slingshot. On my Clone though I can only launch 1 Bird. The second bird will go to the catapault and load perfectly fine. Though once released it simply falls down instead of shooting through the sky.

I figured that there must be a problem with the Physics but I've been troubleshooting for over two days to no avail.

If anyone could offer their advice on this problem t would be greatly appreciated

Here's a link to the project (remove blacnk spaces):

h t t p s : / /w w w. dr op box. com/s/bm1xwh60yf3jsek/Angry%20Birds%20V2.capx