Hmm, it sounds like you might have a mix/match of scripts. You say that you're running 7.2.2, but the header info you have for the libs/ubbthreads.inc.php says it's an older version.
It should have this:
// Ultimate Bulletin Board
// Script Version 7.2.2
It sounds like you need to verify that you actually have all of the 7.2.2 scripts uploaded. The give_rules function that it's looking for wasn't added until 7.2, so that's probably why it's giving the error.
