<p>Douglas,<br>
Well, that is embarrassing; I have been shooting, from 8x10, to 35, since the 80s, but my medium-format has been all Pentax 6x7, and the Mamiya RB67, which has separate cocking and winding. I was, as you suggest, cocking with the crank then winding the already-advanced film right on through. Operator error! <br>
Thank you for the quick, accurate, and complete response!</p>