Out shooting today and noticed that on longer exposures 1sec + what I can only assume to be dust was apparent in the top left of the image. Swapped over the lenses to check it wasn't a prob with these, same prob, so I can only reason it's in the body. The odd thing is, the dust doesn't show up on quick shutter speeds, only the longer ones. I'm assuming this is dust on the sensor (so much so the 400d's sensor cleaning!). If I take it to a camera shop, can they sort this? If so how much will it cost? Quite annoying.