La risposta della NOAA

Hi Giuseppe,
There have been 14 reported cases that I have heard of, 7 of which I
have personally seen. Four of them have been regulators used by our
divers. The other 3 are from other organizations such as universities
and local public safety organizations in the area that we share
information with. Both our organization and ScubaPro have hired
independent testing facilities to examine some of the reg's in order to
determine a cause. I can't speak for ScubaPro, but our tests found no
evidence of overtorquing. It is clear that the current yoke nut design
on the MK20 allows the nut to "bottom out" if over tightened causing
serious stress on the body of the regulator where the cracks have
developed. Supposedly the new design of the MK25 yoke nut has a "collar"
which prevents this from happening. This is on the US versions, and I
have no idea if the European designs are any different. I have heard,
but have no official word that ScubaPro intends to provide their dealers
in the US with the new yoke nuts so that they can replace them for their
customers. I would just talk to your local dealer and see if they have
heard anything or if they know a dealer in the United States that could
forward them the information.
I hope this helps.
Lisa