While watching the web cast, I noticed that balls bounced back out when shooting hard AND soft - seems kind of weird to have a 12 m/s exit velocity if that velocity doesn't match the acceptable entry velocity (upper and lower limits)
I was really surprised by this issue, and it looked like the chains were closed loops in the video - for some reason I had pictured individual strands of chain.
Anyways - here is an interesting item to consider. According to the detailed drawing (link shown below), the chain frame is not symetrical, if assembled incorrectly (back towards the front, instead of front towards the front), the chains would have been closer to the opening than specified - I hope someone checked that because it could account for the balls bouncing out easier at one regional than at the others.
http://www2.usfirst.org/2006comp/Dra...STALLATION.pdf