Hello, My first post on this AWSOME forum. Now the problem. Just bought a Mamiya RZ67 as my first medium format camera and having a bit of trouble with it. The manual states that without film loaded, the camera should work in the M (multiple exposure mode). Now, switching to M allows me to fire off a shot, the lens opens for the right amount of time set on the shutter speed dial and closes after exposure. Right after this i can't advance/cock as the lever sticks. Now i did find that pressing the shutter button a few times more allows me to re-advance/re-cock and re-shoot (still in M mode). The lever advances OK every time when in mechanical 1/400 mode. What could be at fault? Note that i've not loaded a roll yet so this might be a retarded question but please bear with me . Thanks!