Couple things here.  The module is not designed for multiple instances for it on the same page.  While perhaps we should alter it so that it doesn't matter I honestly don't see a reason why you would have multiple forums on the same page.  Why wouldn't you use private forums?  Or perhaps use the group feature where you have multiple pages all based on the same module.  The 'master' forum in this case would be on a page available to the admin only.