During our migration and some of the inevitable database resets involved, many of you who were receiving notifications for new forums topics no longer are. You'll need to re-subscribe.
To do so, simply visit the Forums page, click through to the forum(s) of your choice, and poke the "Subscribe" link that's towards the upper-left-ish of the page. If all you see is an "Unsubscribe" link, then you're already good to go.
Thanks again for everyone who routinely jumps in to offer friendly, helpful advice in the forums!!!