I am a beginning medium format photographer and I would REALLY appreciate some help. I ordered an "excellent" quality Mamiya RB67 Pro-S from KEH camera. The film loaded fine. I tried to push the shutter cocking lever, but it wouldn't budge. It was pointing upwards (towards the ceiling), but I figured that since it wouldn't move that meant that the shutter was cocked. I pushed the shutter release button, and -- success! The problem started when I moved the shutter cocking lever, to re-cock the shutter for my next shot. It moved this time, so that it rested along the focusing knob (pointing outwards, away from me). Once it got to that point, it wouldn't budge again, so I figured that the shutter was once again cocked and ready to go. But when I pushed on the shutter release button, it wouldn't release! The button "pushes" in, but I don't hear the shutter sound and I can tell no picture has been taken. Here are the things I made sure of: 1. My shutter is cocked (since I pressed the lever) 2. My film is advanced (the little #2 is all white, no red) 3. The dark slide is out 4. The shutter safety mechanism (the "release ring") is turned so that it is pointing towards the white dot I have NO idea what I have done wrong, and I don't know a soul who shoots these cameras, so I would REALLY appreciate anyone who can take the time to help me. Thank you!!