after upgrading to moodle 1.7.1+ from 1.5, i choose force everyone to receive an emails when new posts added to fourm, but no one receive any thing.
when i choose dont force everyone, i see the list of my current users BLANK, when i type any letter as search text (E.X : A) i find all my users and add them to the forum manual, so it works and everyone recevice the mail.

i have checked the smtp server, and i installed a new module (fourmtt) , no luck.

i have installed moodle 1.6 on different directory and testes the forum , it works just fine

so should downgrade, or upgrade to 1.8 and the problem will be solved?