17-55 IS strange noise
as a very proud owner of a used 17-55 IS bought on ebay, i mounted it on my 50d, and surprize: o click -shh when i half pressed the shutter , one at the deactivation and some grr-grr in between. strange noises, a little bit louder than the AF ultrasonic. The noises appeared only when IS was activated, but never heard them with 18-55 IS or 17-85 IS.
are there any owners of such lenses who could tell me if those little noises are normal ?