To get this to work, in the Admin-Panel, under the Forums-tab, at every forum the 'display active topics' has to be selected to 'yes';

Looking over the forum-index I can't help notice a lot of subforums haven't got any recent posts in them since a couple of years. One could wonder if they still have any use. If it was my site, I would simplify the forum-structure.
I would suggest the following;
- Group the top-3 'Your'-subforum together into one forum called 'Your Projects'.
- Group the subforums Alcohol, Hydrogen and Ammonia together into one 'Alternative fuels'-forum.
- Limit the market place to 2 subforums, Buy and Sell.
- Delete the entire General Information-forumgroup. Instead, just open a 'General forum' in the maingroup 'Technical Information Forums'.
- Delete 'Dealers' and 'References', and move subforum 'Product Announcements' into the main forum group.
Just my 2 cents...
