Americo, the Pentacon Six is notorious for being very economic with film - I could get easily 24 exposures on a single roll of 120 :-)
Try advancing the film (lever) very slowly and gentle. If this doesn't work and you still get overlapping frames - a trip to a service is well spent money, because the East-German lenses are worth dealing with a quirky camera-body.
I agree, it is indeed a fine lens. But all too often when I get into a new system, I try and buy too many things at once. I've only had my Mamiya 7 for a couple months. I don't need multiple lenses for this camera yet and the 65mm is more than sufficient for me for right now. Maybe in the future I'll look into getting the 43mm again, but it's just a lens after-all.
