My Canon 7D collects dust as this v1 has become my favorite camera. About a week ago, I noticed there were alternating light/dark, horizontal areas in my images that divide the visible image into about five zones ..from the top: light/dark/light/dark/light? I went to shoot some product today and I simply cannot use the camera... The 18.5 lens is clean .. everything seems fine - except the images. I would appreciate any thoughts. Thanks. Jim