[Cryo]

If you change your SQL query to this...

PHP Code:

// run query
$getusers = $db->query("
    SELECT COUNT(p.postid) AS total
        ,p.userid
        ,u.username
        ,u.joindate
        ,f.field7
    FROM
        " . TABLE_PREFIX . "post AS p,
        " . TABLE_PREFIX . "userfield AS f
    LEFT JOIN
        " . TABLE_PREFIX . "user as u
            ON
                u.userid = p.userid            
    WHERE
        p.dateline > $cutoffstart
        AND p.userid = f.userid
        AND    p.dateline < $cutoffend
    GROUP BY
        userid
    ORDER BY
        total DESC
    LIMIT
        $limit
"); 


It should work. The fields you list under the SELECT part of the query determines the results displayed. So if you don't specify you want a field to pull it won't be available in the results. Additionally, because userfields are stored in another table we need to add that with a reference.