If i was you, I would definately look into some new forum software, phpbb3 is close to full launch. I would also look into a permanent domain (newzforums.com?) - this might make it easier for people to remember the URL. Also, sending out regular emails (latest posts, news, guides etc) will drive people back to the forum.
One final point, you have 13 forums, all uncategorised, most are pointless, maybe get rid of some, and categorise the others? I would lose Newbie Central, Forum Announcements, Forum Suggestions, Computer hardware, and Newbie Central. I would create a new forum for Forum Info for announcements, suggestions, and other info, I would merge Newzbin and Usenet discussion, aswell as Newsgroup Clients and Newsgroup Providers. I would also merge Movie and Gaming sections, renaming it to 'Movie, Music and Games Reccomendations'.
I know it seems like alot is dissapearing, but unless the forums are being regularly used, whats the point in them? If the board gets busy again, then you can slowly reintroduce certain forums.
Also, a quick Q, are we allowed to link to a post on newzbin? Maybe start a new section about reccomended newzbin reports?