[eluser]sophistry[/eluser]
ok, now it is clear this is not an imap_pop library issue... imap_pop is a lib i wrote to make it easier to get email into CI. but, it appears that you are not using it, so i don't know why you posted in this thread. :-)
in fact, the imap_pop library does not support imap_search().
i'm sorry, but you'll probably find better help in another thread or on a forum dedicated to PHP IMAP functions.