First of all I apologize for not having already replied.
When I had this drawback, I was still on holiday in Sardinia living in a small village without internet availability. That evening, I was so bad temperament to drive for a while to find a Wi-Fi point and write to APUG.
Thanks very much for your posts where there are some questions to be analyzed quickly.
I have been requested to describe in detail what happened and in what order:
1. After I pressed the release button, I had the clear impression that it went to stop itself at half of the usual trip, I heard only the deep sound of one shutter and I retain that one from the central body.
2. To go over the block I had to stop the pressure and to push again, hearing this time the second classic sound from the lens.
3. This occurred modifying both the aperture and the speediness from one second to 1/500, till the end of the film(400 ASA).
4. I had also the impression (… impression because I was nervous with my hands trembling) that the camera was blocked while I was sure that some shots were regular before to return irregular.
5. This camera was unutilized for more than one month remaining cocked.
6. Concluding with another remark, this time I did not utilize the flexible cable release button I usually do with Hassy.
I hope to have encouraged you to write down others precious experienced opinions.
Especial thanks to all of you.