I am new to this game i have had my 400d for two weeks now and i havea lot of dust showing up on some of my blue sky shots should i take the camera back to the shop or is this a common fault with this type of camera.The self cleaning thing does not seem to be doing much of a job,have u herd of this problem with this camera outher than that it is great.Ps i have had the lens on the camera since new not took it off.

