At the moment it appears that your forums are ordered by date of the original message in a thread. This means that if someone adds something to a thread started over a year ago (as I've just done), then this will stay potentially a few pages back and is not so easy to notice by new visitors.
Is there a way to set the forums up so that they are in order of the latest date something has been added to a thread? Would certainly make it easier to watch/participate in any of the more 'popular' discussions.