Hi all, I just purchased an M4 with a collapsible 50mm Summicron. And I've been having a problem mounting the lens, wanted to see if anybody had the same problem with me. Basically the lens doesn't rotate until it clicks, instead it gets stick right before it reaches the end. The Dropbox link below has photos of where it stops, and inside of the mount. Dropbox - m4 - Simplify your life I'm going to take it to a repair shop on Monday, but wanted to see if this is a simple problem that I can solve tonight so that I can take it out tomorrow.