CodeIgniter xmlrpc Did not receive '200 ok'

I'm trying to implement an xmlrpc server/client per the CodeIgniter User Guide. I've taken th开发者_如何学运维e code as is and keep getting

Did not receive a '200 OK' response from remote server.

I'm running PHP 5.2.1 on the server. A quick google search leads to http://codeigniter.com/forums/viewthread/63287/ which does not help. I've also tried modifying my Xmlrpcs.php file under system/libraries without success.

So what IS CI actually sending back? Setup test using Firebug and CUrL might help.

I use a CI install with "ajax" controller which handles its own AJAX requests.