Select Activated Users

Hi

I am trying to get a list of all users that are activated using this code:

<?php
$blogusers = get_users(array('meta_key' => 'activate_user', 'meta_value' => '1'));
    foreach ($blogusers as $user) {
        echo '<li>' . $user->user_email . '</li>';
    }
?>

But it doesnt work – any ideas?

http://ww.wp.xz.cn/extend/plugins/wp-members/