Maybe there was a post there to make sure the ball wouldn't get stuck in that spot...due to the non-working kickback. Once you take it apart and clean/reassemble, hopefully you'll find the problem's fixed.

One thing to note: i have had the plunger on a kickback magnetize--it would work sporadically. Drove me nuts until i found out about the plungers occasionally magnetizing on them for whatever reason. So if everything looks good, you may want to try a new plunger for the kickback.