I recently picked up a Canon new F1 of E bay and it has a film transport problem. About every other roll of film I can go to about frame 4 and then everything jams up. When I open the back, the film has been folded with a nice sharp crease and stuffed between the take up spool and the sproket roller. This happened twice today, even though I first put the film on the take up spool, and advanced the fim to make sure it was tight and then pulled the film across to make sure it stayed tight. Is this a common problem with New F1's? I also have an original F1 and it has never had a problem, even though take up mechanisms look very similar. If it makes any difference I do not have a motor drive on this camera.