Also I can't hurt to check on this setting in your UCP in the "Edit Posting Defaults" section.
I'm not sure it's necessary or not however if subscribing to topics or forums (below) does not work for you then this could possibly be why.
Once you have these settings the way you want them you should be able to subscribe to various topics and forums on the board.
To subscribe to an entire forum (room) look for the "Subscribe Forum" link at the bottom of the forum you are visiting. To subscribe to an individual topic, first open the topic, then look for the little drop down box (with the little wrench) next to the Reply button. Click the link for "Subscribe Topic" follow that particular topic. Hopefully this works for those of you who wished for these options... please keep in mind that we are still tweaking the settings here so if it doesn't work for you please let us know and we'll keep at it until we get it set up right.
