Some separation is good.. too much kills a forum. Banter and cross-pollination of ideas is fundamental to a healthy and vibrant forum environment.
I've suggested a slightly different approach previously - along the lines of using the "category" field to provide the separation (if you want to use it). Setting the Category needs to be compulsory on a new post.
Fundamentally, all the windsurfing posts would be in the windsurfing forum. At the same level. Sub-forums are approximated by choosing the "category" you want to look at. With a little bit of imagination, Laurie could even hook that into the menu, so it would even look and work the same for the people who like to use it that way.
That keeps Greenroom happy (Ah.. modern democracy - it's always the minorities that hold sway) because he can still look at the categorised posts [he can even still call them sub-forums if he likes
], it keeps the rest of us happy because we can regain that "big fuzzy family feeling", and best yet, it doesn't upset the "Active Topics" functionality.
The important thing is that it needs to be easy to use, and easy to see that things are alive on the forum. As a new visitor, you're not going to understand about all the sub-forums, and as firie just demonstrated, the 'Active Topics' thing isn't intuitive to find/use.
Bring back Bubs!
, that'll do the trick for me too mate 
...er so, change it back to how it was before it was unchanged.......I mean changed.......(pre change)... So thats a no to change, except for the change back.................yes. 
