I have a 1939 Rolleiflex New Standard; on the bottom of the camera is a red window which one is supposed to use to advance the film for the first exposure, then the winding mechanism automatically advances to the next frame.
When looking at the bottom of the camera with the front of the camera facing you, the red window is on the left. In this position, after you have loaded the film, the numbers appearing in the window are not the numbers for 6x6 frames; they're the numbers for a longer (6x8 or 6x9) frame and end at "10". At least on modern 120 film, the numbers for 6x6 are in the center of the paper backing.
Since the "1" for the longer frames is further down the roll than the "1" for 6x6 frames, when I advance the film so that "1" shows in the window, I've already advanced it almost to the second frame (the "2" mark,) for 6x6 frames. Essentially, I'm losing the first frame from every roll of film!
Did they change the placement of frame numbers at some point, or what?