Hmmmm did you add the code to adduser.php?
// -------------------------
// Build Board Query For Shop Mod & Insert Points
// Add user to Shop
$query="
INSERT INTO {$config['tbprefix']}ShopMembers
VALUES ('', '$Uid', '$Displayn_q', '$Title_q', '$Picture_q', '', '', '', 'OFF', '$Color_q', 'OFF', 'OFF', 'ON')
";
$sth = $dbh -> do_query($query);
// End of Build Board Query For Shop Mod & Insert Points
// -------------------------
without that they won't get added to the w3t_ShopMembers table when they are added as a new user to the board?
it has to be UNDER
// Get this user's user number
$query = "
SELECT U_Number
FROM {$config['tbprefix']}Users
WHERE U_Username='$Displayname_q'
";
$sth = $dbh -> do_query($query,__LINE__,__FILE__);
list ($Uid) = $dbh -> fetch_array($sth);