You must have added a hack at some point ;
Replace the code with this and it should be ok ;
PHP Code:
// Paul M Proxy Hack v1.31x
// ### POST NEW POST ###
$DB_site->query("
INSERT INTO " . TABLE_PREFIX . "post
(threadid, parentid, title, username, userid, dateline, pagetext, allowsmilie,
showsignature, ipaddress, proxyip, iconid, visible, attach, useragent, altip)
VALUES
($threadinfo[threadid], $parentid, '" . addslashes($post['title']) . "',
'" . addslashes($post['postusername']) . "', $bbuserinfo[userid], " . TIMENOW . ",
'" . addslashes($post['message']) . "', $post[enablesmilies], $post[signature],
'" . addslashes($post['ipaddress']) . "','" . addslashes($post['proxyip']) . "', $post[iconid], $post[visible], $totalattachments,
'" . addslashes($_SERVER['HTTP_USER_AGENT']) . "', '" . ALT_IP . "')
");
// End Proxy Hack