Nope I get that on my canon sensor all the time. I think personally it is a flaw in the sensor, since I sent it in and spent a ton of money having them clean it. Never again. I will clean it myself or shoot it through the fracking lens. I still get that on sky shots all the time. I have to clone it out if I care. Really annoys me. It is one of the reasons I am moving away from the rebel body I have. I can't afford a new body, so I guess I will just have to figure out how to live with it.