On your profile, under your avatar, it shows some information and stuff. One of it is the forum section your active in. How is that changed? It's harder for me to access the Community Discussion forum if it's not shown there. Right now it shows:

Active In:
Skyrim General Discussion (2142 posts)

I haven't even posted in the Skyrim General Discussion in a long time and I've been posting in the Community Discussion a bit, but nothing has changed.

I think you're active in the forum where most of your total active posts are, not recent activity.

I'm pretty sure the "Active In" section is relative to how many posts you have made in a given section. So, if you reach 2,143 posts in a different section you will become "Active In" it.

Edit* ninja! :ninja:

Well, ouch. I guess I'll have to post twice what I've posted to be active here.

You know you can go to any forum index and at the bottom it has CD?

My most active forum is Community Discussion, but it has 13% of my posts. I guess I'm all over the place.

Yes, but it isn't as fast or convenient.