Does anyone have experience of using Leica R4 and 5s with a motordrive? I have an R4 and have trouble with its motordrive being unreliable at actually winding the film. Both camera and drive have been checked out and work fine and the motor drives the camera quite happily empty, but won't always wind on all the way with film loaded. I discussed this with our local Leica dealer who told me that I should get an R5 (or 7) body because, as well as the advertised advances over the 4, it was a generally better engineered machine and winds more easily. 2nd hand prices are getting so low that this won't break the bank but I thought I'd ask to see if anyone else has faced this issue.