Obviously I would look into the sleeve first. Then I would look at slightly adjusting the shooter lane metal guide. I seem to recall at the top of it, under the plastic near the kickback lights, it has an adjustable slot for the top screw that holds is down. You may be able to angle it a little more to help you out.
Quoted from Chet:I am having a little issue of the ball launcher not getting the ball into skydive scoop consistently.
Quoted from RacerRik:I have the same problem. I have tried a bunch of things to fix it and it is better now, but still misses a fair percentage of the time.
EDIT: Yep Moondrummer beat me to it.