My lens has the same issue. I was told by the store that the zoom brush needs to be replaced but they don't have the new part yet (it's almost 1.5 month now since I brought the lens in). I was also told I could use the lens as is, without implications, until they get the part and replace it.
Anyway, my question is, does anybody know if I can really use the lens without further damaging the zoom brush or other internals?
did the lens always have the 'clicking' sound on the zoom ring, or did it start after having it a while? i sent one back for replacement as documented in this thread.
also you say 'the store' are getting the new part in. hopefully if you are getting it fixed rather than replaced then this store is not just a retail store but a Canon approved service centre?
interesting though that i've come across quite a few people now on forums who have had an issue with this. i felt like the only one when i first posted about it.