[Carnage]

ok; it is doable, however theres an aditional edit that needs to be made around line 604 find:

PHP Code:

        // REQUEST_URI is dependable for apache
        if (isset($_SERVER['REQUEST_URI']))
        {
            // return the raw url
            $url = $_SERVER['REQUEST_URI'];
            $url = $this->registry->input->strip_sessionhash($url);

            return $url;
        } 


Replace

PHP Code:

$url = $_SERVER['REQUEST_URI']; 


with

PHP Code:

$url = 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI']; 


I dont know if this will have any knock on effects elsewhere, but it seems to be working for me on my dev board. You'll need to set a server alias for forums.yourdomain.com to be the same as yourdomain.com in apache and you'll also need to edit the cookie [s]path[/s] domain to cover your entire domain (eg set it to .yourdomain.com). Once you've done this, if you set threads to http://forums.yourdomain.com/threads and forums to http://forums.yourdomain.com with a bit of tweaking, you should be able to get it right.