Andymark pneumatic wheel problems
 

Several people on our team were looking at online videos for frisbee shooters and similar products and settled on the Andymark pneumatic wheel for our robot this season. We ordered a couple and started testing, but we are not getting very far because our wheels are out of balance/round.
Wondering if anyone else has had similar issues and if they found a solution?

See the wheels in action here:
http://www.youtube.com/watch?v=GT88vWTYgj0

and sold here:
http://www.andymark.com/product-p/am-0970.htm