Looking at the picture of 35mm summicron v4 in the book Leica Compendium 2ed, you can see that the two pins on the lens do not align perfectly. This is exactly the same as my 35mm summicron v4. Thus, I am having the same issue with the hood.
Originally Posted by maddoc
I had a version 3 28mm Elmarit a couple of years ago (with hood having a cut-out to reduce VF blocking) and remember that it had two spring-loaded grooves in the hood and two pins on the lens barrel to fix the hood. (Similar to the Noctilux) If one of the springs is bent the hood might not be properly installed on the lens. Also make sure that the front part of the lens is not twisted, the two pins have to be oriented exactly up-downwards when the lens is mounted on the camera. (I had a vs4 35mm Summicron, where the front part was slightly rotated and therefore also the lens hood ...)