I have observed similar in several of the Premiere fora today, August 07, 2010. A lot of 1 - 2 year old threads are at the top of the list, and none have had a reply in that time - nothing more recent than 1 year ago. None is showing up as "Updated," and just at the top of the thread list.
Something is not right, and it seems to have come about since 11:00PM PDT August 06, 2010, when I logged-off.
One of the most prolific posters to those fora, Harm Millaard, just lost his profile, in the same time period, though that might not be related in any way.
This happens when spam posts are appended to old topics, and then deleted by forum mods - the old posts stay on top of the forum. Yet another nuisance caused by spammers!