Problem with Tiny Portal

$request = db_query("
SELECT
m.icon, m.subject, m.body, IFNULL(mem.realName, m.posterName) AS posterName, m.posterTime,
t.numReplies, t.ID_TOPIC, m.ID_MEMBER, m.smileysEnabled, m.ID_MSG, t.locked, t.numViews,t.numReplies
FROM ({$db_prefix}topics AS t, {$db_prefix}messages AS m)
LEFT JOIN {$db_prefix}members AS mem ON (mem.ID_MEMBER = m.ID_MEMBER)
WHERE t.ID_FIRST_MSG IN (" . implode(', ', $posts) . ")
AND m.ID_MSG = t.ID_FIRST_MSG
ORDER BY t.ID_FIRST_MSG DESC
LIMIT " . count($posts), __FILE__, __LINE__);

$request = db_query("SELECT art.id, IF(art.useintro>0, art.intro, art.body) AS body,
art.date, art.intro, art.useintro, art.category, art.frontpage, art.subject, art.authorID,
art.author, art.frame, art.approved, art.off, art.parse, art.comments,
art.comments_var, art.views, art.rating, art.voters, art.ID_THEME, art.shortname,
art.sticky, art.fileimport, art.topic, art.locked, art.illustration,art.type,
mem.realName, mem.avatar,
IFNULL(a.ID_ATTACH, 0) AS ID_ATTACH, a.filename, a.attachmentType
FROM ({$tp_prefix}articles AS art, {$db_prefix}members AS mem)
LEFT JOIN {$db_prefix}attachments AS a ON (a.ID_MEMBER = mem.ID_MEMBER)
WHERE art.category=$mycat
AND art.off=0
AND art.approved=1
AND art.authorID=mem.ID_MEMBER
ORDER BY art.$catsort $catsort_order
LIMIT $start,$max", __FILE__, __LINE__);