the only real purpose those little circular pads on the top and at the ends of the leaves are for eliminating squeaks as the spring extends and compresses while driving, i think my rusty's leaf packs may still have one intact out of all of the leaves and the squeekiness isn't even noticable, no where nearly as bad as stock leaves w/ an AAL installed..
what you're experiencing is normal for those springs maybe call rusty and complain or not, either way they'll be fine, they just disappear somehow, friction/heat or something causes em to pop off