[Mailman-Users] I can't turn off password reminders for my users

[sweepslate]

I created a list and then turned off reminders in the admin UI. Here are 
the relative options:

   umbrella_list no
   send_reminders off

After that I've subscribed 3 mail addresses that belong to me, as a test.

Checking the web preferances for each newly registered user I see that 
they have the reminder option turn on: "Get password reminder email for 
this list?".

My question is, how can I turn off password reminders for all new users 
arriving on the list?