public function fetch($spec = null)
    {
        if ($spec instanceof Solar_Uri_Action) {
            // a URI was passed directly
            $uri = $spec;
        } else {
            // user spec is a URI string; if empty, is the current URI
            $uri = Solar::factory('Solar_Uri_Action', array(
                'uri' => (string) $spec,
            ));
        }
        
        // take the page name off the top of the path and try to get a
        // controller class from it.
        $page = array_shift($uri->path);
        
        if (empty($page)) {
        	array_unshift($uri->path, $page);
        	$class = $this->_getPageClass($this->_default);
        } else {
        	$class = $this->_getPageClass($page);
        }
		
        // did we get a class from it?
        /*
        if (! $class) {
            // put the original segment back on top.
            array_unshift($uri->path, $page);
            // try to get a controller class from the default page name
            $class = $this->_getPageClass($this->_default);
        }
        */
        
        // last chance: do we have a class yet?
        if (! $class) {
            return $this->_notFound($page);
        }
        
        // instantiate the controller class and fetch its content
        $obj = Solar::factory($class);
        $obj->setFrontController($this);
        return $obj->fetch($uri);
    }