Dear all, I have a Mamiya M645J, which gave me several problems lately and I am not sure whether it's a light leak or a problem with the shutter curtains - or maybe sth else. Any ideas? (The problem occurred with the last 2 films. At the first film of these two, it was just one picture; at the 2nd film, it happened several times. I haven't used the camera since.) Your help is much appreciated - thank you very much in advance.