Thanks jol and HaQue. I usually make my links to the unread posts shortcut too, but don't know why I didn't have it for this forum.
Edit: I see I have it set to search.php?search_id=newposts
. I'll change it.
Edit #2: Now I see why I used new posts rather than unread posts: I may not be interested in reading every unread post. Next visit, they are still included in the list of topics. The solution of course, is to go to the forums root and click mark all read. Babbling away to myself again...