ok, if you still want the banned list without having the users show in thw show groups remove usergroup.showgroup = 1 so it looks like this. remember to change 9 to your banned usergroup
PHP Code:
// get banned users**********************************************************
$users = $DB_site->query("
SELECT
$banreasonfieldselect, usergroup.title, user.username, user.userid, user.invisible, user.receivepm,
user.usergroupid, user.lastactivity, user.lastvisit, $banuntilfieldselect
FROM usergroup
LEFT JOIN user ON (usergroup.usergroupid = user.usergroupid)
LEFT JOIN userfield ON (userfield.userid = user.userid)
WHERE usergroup.usergroupid = 9
");