We got a very very big problem.
I'm testing our new website wich must be available within 1 week.
I've notice that, when I modify a user's plan from the back office (Activation, Renewal, Deactivation..) it somtetimes change the user's password into the jos_users table !!
It doesn't happended every times.
I am testing different situations, because we got different plans and sometimes they interact.
I have the same problem with front activation. For exemple, I create a free registration as I was a simple user, so I recieve a confirmation email in order to click on th eactivation link... After the activation I can't connect in frontend !