Here's ours, which sounds like it's working about the same as theirs.
http://www.youtube.com/watch?v=jeLe2WWemWA
We never got around to trimming the top of the shooter, so the students are holding it at an angle. It's not quite 45 degrees. There is a Lexan flap behind the shooter, that is being held down over the top of the ball before inserting the ball into the shooter.
http://www.youtube.com/watch?v=jeLe2WWemWA