Anyone know the answer to this one? I have a Contax II, and it seems to be in good shape - except for this: on slow speeds after the shutter is fired, when I begin to wind for the next shot, as the top curtain is rising it is often the case that the lower curtain separates such that the film is exposed. On high speeds, the curtains fall quickly and the top curtain and bottom curtain lock together. Then as they rise together for the next shot, they provide a light-tight seal. But on low speeds, often as not, they fail to lock and rise together. Failing to lock together, this leaves separation of various widths between the top and bottom curtain as I wind the camera. Sometimes after cocking is complete, the lower shutter is left hanging only half way up across the film exposure openning. Does anyone know what is wrong with this camera? Is there an easy adjustment for this? Thank you.