that thread seems like it's geared more towards chat and other realtime multiuser stuff. Forums/Message boards are difficult in Flash to say the least. The best one's i've seen are still slow and don't organize the data as well as they should. The style I like the best is created by duplicating a movie clip a set number of times (corresponding to the number of entries in the DB) - then each duplicated movie clip has an instance name say ID1 or ID2, etc. Data from the database is loaded into a text field contained in each corresponding instance of the movie clip. These are in essence topics. You can then reply to the message in the movie clip - which adds on to that database entry. Each time you update or add to a topic it gets updated therefore the timestamp or last modified date becomes the most recent, moving it to the top position.
Well at least it's better then a threaded discussion. Anyways that probably made no sense whatsoever. Later.