Sorry the GROUP BY goes before the ORDER BY.
PHP Code:
$get_recip = $vbulletin->db->query_read("
SELECT recipid, categoryid, sitetitle, username, userid, sitelink, sitelinkimg, aboutme, views, votes, rating, joindate, active
FROM " . TABLE_PREFIX . "recip_links
WHERE active=1 GROUP BY categoryid ORDER BY joindate DESC, categoryid ASC
LIMIT " . ($limitlower - 1) . ", $perpage
");