I recently bought an ETRSi outfit. It came with an early style 120 back and an Ei 220 back. I haven't used the 220 back yet, but I bought an Ei back shell to replace the early one, which was damaged, and I'm still using the early 120 insert. I've only run two rolls of film through it so far, and I'm having spacing issues. I have read that, with other cameras, spacing problems can occur if the film wasn't loaded optimally. So I'm thinking this might be the problem here. With both rolls, the first frame was partially exposed prior to it being taken. Also with both rolls, frame spacing varied from an overlap of maybe 1/32" to gaps of over 1/2". Because of the large gaps on one roll, I got only 14 exposures. I know it was my own clumsiness that led to the partial exposure of the first frames. I thought I was being careful, but I guess I wasn't being careful enough. I was also conscientious about taking out all the slack I could before loading the roll into the insert and before loading the insert into the back. The manual mentions that the preferred method of loading film is with the back attached to the camera, and using the camera's film wind crank to advance the film to the start position. I haven't tried this method yet, but it seems to me that it shouldn't matter whether it's done that way or with just the insert alone. Because the spacing differences appear to be occurring on a random basis, I don't know what to think. Maybe this old insert is worn out and needs repair? The gear that engages a gear in the body doesn't show any significant signs of wear -- and neither does the gear in the body -- and it doesn't slip at all when I turn it. So, I dunno. So if you have any tips to pass along, I'd sure appreciate it.