[Admin]

OK stick this in your functions.php:

// ###################### Start unindexpost #######################
function unindexpost($postid,$title="",$pagetext="") {
	global $DB_site;

	// get the data
	if ($pagetext=="") {
		$post=$DB_site->query_first("SELECT postid,threadid,title,pagetext FROM post WHERE postid='$postid'");
	} else {
		$post['postid']=$postid;
		$post['title']=$title;
		$post['pagetext']=$pagetext;
	}

	// get word ids from table
	$allwords=$post['title']." ".$post['pagetext'];
	$allwords=preg_replace("/[\n\t\r,]/s"," ",$allwords);
	$allwords=preg_replace("/(\.+)($| |\n|\t)/s", " ", $allwords);
	$allwords=str_replace("[", " [", $allwords);
	$allwords=str_replace("]", "] ", $allwords);
	$allwords=preg_replace("/[\(\)\"':;\[\]?!#{}_\-+\\\\]/s","",$allwords);
	$allwords=strtolower(trim(str_replace("  "," ",$allwords)));
	if ($titlewords)
		$allwords.=" ".$titlewords;
	$wordarray=explode(" ",$allwords);

	$getwordidsql="title IN ('".str_replace(" ","','",$allwords)."')";
	$words=$DB_site->query("SELECT wordid,title FROM word WHERE $getwordidsql");

	$wordids="";
	while ($word=$DB_site->fetch_array($words)) {
		$wordids .= ',' . $word[wordid];
	}

	// delete em!
	$DB_site->query("DELETE FROM searchindex WHERE wordid IN (0$wordids) AND postid=$post[postid]");

}