I am not returning it just for the occasional click, chances are, that will also be resolved with next weeks firmware updates. Like I said before, clicks are very common from OIS, from lenses, or sensors etc, all my camera click when they kick in, I am not worried about it at all. If it was vibrating and constantly doing it like the main issue, sure, be worried, but the fact it does once (when its initialising) I don't see any issue with, specially as it does not always do it, as far as I'm confirmed, mechanical OIS makes a noise.