Hello folks! I'm new here even though i've been lurking and following you since i got my first MF camera, a beautiful RB67 Pro-S. After a month of inconsistent results due to a then unknown problem with the system, i've been recently trying to detect it. Basically the issue involves both the top left (as seen from behind/film back) coupling arm and the revolving adapter. Here three different scenarios in which the problem emerges: 1) no revolving adapter attached (in video from 00:00 to 00:30) - The coupling arm behaves normally, no irregularities whatsoever. 2) Revolving adapter attached (in video at 01:01 and at 01:06) - coupling pin stands out a bit longer than it should. I presume this is because of the underlying coupling arm being stuck for a time long enough to undermine the proper working of the motor drive back, which i own. I've lost two roll of film because of this, as the motor drive continued to wind up skipping most of the frames before the coupling pin went back to it's retreating position. 3) Revolving adapter tilted (in video at 01:23) - although this is not an usual shooting situation, this is to show how the problem emerges, with the coupling arm not getting back to its resting position. Usually it does so after a couple of second, enough to undermine, as already said, the proper working of the motor drive. Meanwhile i've got a pro-SD manual back with, and it does not seem such an issue anymore since i usually wind the film after enough time to let the pins get back to their resting position. What puzzles me about this is how inconsistent the problem comes in light, it can happen four times in a row and the disappearing for another 10 frames. Second, i'm struggling to get why does this happen only when the revolving adapter is sitting on the body. As shown in the first part of the video, in its abscence, all is working regularly without any trouble for 20+ shots. Before peeling off the leatherette and disassembling the left panel, i'd like to ask you help. That would be extremely appreciated. Thanks!