I have the DR and if you remove the plastic peg from the goggles it will work on the M9. The top plate of the M9 is a few mm taller than the film body top plates and the plastic peg, which is designed to rest on the top plate, prevents the goggles from being attached to the lens. Close focus works on my M9M but when the "close focus" mode is not engaged the lens will not focus to infinity. You do not need the goggles to set the lens to close focus, but you might need to attach the goggles in order to focus.
If your having trouble mounting your DR to you digital body, ensure that the lens isn't focused to infinity. I like the DR a lot, particularly on my MP. I've been thinking of having it modified so that it will focus to infinity on my M9M, but I also have a 50mm lux...