I migrated my forums off to BBPress, which solved the problem for those. They're now starting to get indexed, and we can also take full advantage of the WPSEO settings to manipulate the metadata (if we ever have time to do something like that for forums).
http://indietravelpodcast.com/forums
Unfortunately, after hours of creative play we couldn't get them playing nicely with the BP group-based stuff at all. I think there are some changes coming in 1.7 (which is due soon), and it might be worth holding off for them: I know there are changes around how forums are done, but don't know the details.