Anyone had their mount replaced? When the Voigtlander 35 1.2 is used the lens rotates freely in the mount. It doesn't happen with other lenses, I went to Calumet the other day and put the lens on an M6 and it didn't budge.
Funny you should bring this up ........
I just bought a 90/2.8 Elmarit and this lens is doing exactly what you just described. I bought my RD1s used about 6 months ago (6k clicks), and just found out that I can rotate this lens off of my RD1s mount if I put a reasonable amount of pressure on it and rotate it right off. I Then put the same 90/2.8 on my M6 and it does not rotate off. I hope someone can give us more info about this issue as it seems more common than I realized.