很多咬牙，这似乎工作：

After much gnashing of teeth, this seems to work:

function doPost(){

    $this->load->library('xmlrpc');

    $bloguser = "theUserID";
    $blogpass = "thePassword";
    $blogid = 1; 
    $publishImmediately = TRUE;

    $thePost = array(array('title'  => array('this is the title','string'),
                            'description'    => array('this is the description','string')
                            ),
                     'struct');               


    $myPost = "my post";
    //$this->xmlrpc->set_debug(TRUE);
    $this->xmlrpc->server("http://url.to/xmlrpc.php", 80);
    $this->xmlrpc->method('metaWeblog.newPost');

    $request = array($blogid, $bloguser, $blogpass, $thePost, $publishImmediately);

    $this->xmlrpc->request($request);
    $result = $this->xmlrpc->send_request();

    if ( !$result )
    {
        echo $this->xmlrpc->display_error();
    }
    else
    {
        echo '<pre>';
        print_r($this->xmlrpc->display_response());
        echo '</pre>';
    }
}

重要的是注意元素的结构的实际职位。

The important part is to note the struct for the elements of the actual post.