delete_post_index isn't working

[Oreamnos]

Well, it's not working for me, at least.

I am trying to manually update some posts and make sure the the search index stays consistent with the posts' text.

i have tried many different ways to get delete_post_index to work but everytime i search for a word that used to be in the post but is no longer there, i still get search results that says the word is in the post.

here are a few different queries i have run but with no luck. any ideas of what i am doing wrong?
// Reindex first post to set up title properly.
$getfirstpost = $db->query_first("
SELECT postid, title, pagetext
FROM " . TABLE_PREFIX . "post
WHERE threadid = $threadid
ORDER BY dateline
LIMIT 1
");
delete_post_index($getfirstpost['postid'], $getfirstpost['title'], $getfirstpost['pagetext']);

build_post_index($post['postid'], $post['threadid']);

i've also tried this:delete_post_index($postid);
build_post_index($postid, $foruminfo);