He has to run an option in the admin panel to "rebuild search index" or some such crap. It is one of the first things they tell you to do in the instructions on how to upgrade from phpBB 2.0 to 3.0.
Another thing he has to do is install a mod/hack so that whenever you reply to a topic, it doesn't automatically repost the topic's title in the subject line (otherwise you have to remove it manually, as I did, for example, with this post). This makes threads look much less cluttered.
All of this should of course be done automatically, but "open source", etc.