that is probaly some dust one you lens, one the mirror or the Image sensor. if its on the lens, itds just to clean it with a q-tip or some fabric, if its is on the mirror you have to be VERY clean, because its very easy to get more when you first are in there, if it is on the Image sensor I would send it in for cleaning. If the cam is new and you havent messed with it, you could go to the store and get a new one, if you are lucky,
but you could always take the blure away in photoshop. you have to do it in every photo, but its doeble..
good luck