I've never used a medium format camera before, so please answer in the most elementary language possible. I bought a Mamiya RB67-S camera on eBay, and just got it, and have been trying to learn how to use it. I've gone through about 6 rolls of 120 film already, before I was finally able to get a single shot -- just learning how to load it, and advance the film was giving me an amazing amount of trouble. I kept having trouble getting to the second frame of the film. I finally found a way around the problem, but it seems so strange, that I am wondering if there is something wrong with the camera. Here's the thing... I've finally gotten the film loaded correctly, and advance the film to the 1st frame. I cock the shutter, and press the shutter button, and it takes a picture. That's the only one it wants to take though. From there, the camera wants to lock up on me, and won't allow me to advance the film with the film advance lever. The camera back seems to be on properly, with the S-lock in the proper position. Of course, the dark slide is not in... and the shutter lock is not on. It is not set for multiple exposure. What it wants me to do is manually move the "film wind stop release lever" to the right before I am allowed to advance the film. It took a lot of film before I figured that one out. The manual leaves much to be desired, and I am having a hard time learning how to use this from that alone. Does anyone who owns this camera know if this is normal, and if it's not, why that solves the problem of advancing the film to the next frame? I was finally able to get a roll of film with a few exposures, but only after using that little lever before taking every single picture. I've taken a pic of the lever I'm talking about, and circled it. The only thing I can find in the manual about that lever is: "The film wind-stop is released manually by this lever only when the Pro-S roll film holder is used for the Mamiya Press", and "the film wind-stop release lever provided for the Pro-S roll film holder is to be used when the holder is used for the Mamiya Universal Press, or when desiring to wind up to the film end while unexposed film remains in the holder" and "when the shutter is released, the film wind-stop mechanism is automatically disengaged, and the film can be advanced for the next frame." Well, it doesn't seem to be doing that automatically, and since I'm such a novice, I have no idea what a "Mamiya Universal Press" is, or why I have to shift that little lever for every shot. Is there a defect? And if so... would it be a defect just with the back, or with the camera body?