Have a strange problem whith mine. When i had connected a thread releaser to the side on this camera it sometimes trigger the shutter all by it self random, and i dont need to touch it.
And only when the thread-releaser is there not just the adapter. Got two of these mamiya adapters, same problem. And shutter time is random, long or short regardless what the shutterspeed dial is set on.

Cuold it be static electricity?
Anoys me to waste film! Anybody else have this problem?