SOLVED: XMLRPC throwing error because returned data is not an array

[eluser]Unknown[/eluser]
Solved: I thought the error was regarding the returned data, but it's actually about sending $request as a blank string parameter instead of as a blank array. Changing $request='' to $request=array() fixed the problem.

I'm trying to use the XML-RPC library to get a cookie value from livejournal.com. The getchallenge method doesn't require any parameters. Through $this->xmlrpc->set_debug(TRUE), I can see that the server is returning the correct data. However, CI's Xmlrpc.php keeps throwing an error because the data returned is not an array.

My questions:

Why is Xmlrpc.php expecting an array instead of the XML string that's actually returned?
How can I get around this error and actually use the data that's being returned?

Much thanks for any help!

Error:

Code:

A PHP Error was encountered

Severity: Warning

Message: Invalid argument supplied for foreach()

Filename: libraries/Xmlrpc.php

Line Number: 209

Returned from server:

Code:

---HEADERS---
HTTP/1.0 200 OK
Date: Wed, 23 Sep 2009 03:30:43 GMT
Server: Apache
Set-Cookie: ljuniq=VyFuIsC8VNG9daa:1253676643:pgstats0:m0; expires=Sunday, 22-Nov-2009 03:30:43 GMT; domain=.livejournal.com; path=/
Content-Length: 510
Content-Type: text/xml
SOAPServer: SOAP::Lite/Perl/0.60
Connection: close
---END HEADERS---

---DATA---
&lt;?xml version="1.0" encoding="UTF-8"?&gt;<methodResponse><params><param><value><struct><member><name>auth_scheme</name><value><string>c0</string></value></member><member><name>server_time</name><value><int>1253676643</int></value></member><member><name>challenge</name><value><string>c0:1253674800:1843:60:BV9RGJxRODz3O5IFy8YN:2cd6ceeb986bbbdb7ec59903c99cea2c</string></value></member><member><name>expire_time</name><value><int>1253676703</int></value></member></struct></value></param></params></methodResponse>
---END DATA---

Code in my controller:

Code:

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

        $this->xmlrpc->server('http://www.livejournal.com/interface/xmlrpc', 80);
        $this->xmlrpc->method('LJ.XMLRPC.getchallenge');

        $request = '';
        $return = $this->xmlrpc->request($request);

        $this->xmlrpc->display_response();

        if ( ! $this->xmlrpc->send_request())
        {
            echo $this->xmlrpc->display_error();
        }