This is just a suggestion, but I don't think the automatic forum updates whenever the main blog is updated helps the forum. I'm pretty sure everyone who reads and posts at the forum is already an avid reader of the blog, so it doesn't really get the blog any extra exposure. Meanwhile, on months with a lot of posts, like any month where there's an ongoing contest or theme, the update posts push a lot of interesting topics off the front page. Additionally, no one comments on those forum threads because it makes more sense to comment directly on the blog posts instead. Having all those forum threads with no activity helps give the impression that the forum is slower than it actually is.
I think more effort to make blog readers aware of and participating in the forum rather than vice versa is what's needed.