xmlrpc unsupported method call with php
===

I have a method on a remote IIS server at somefile.ashx, one of the methods I'm trying to call is 'UserLogInReq'.

UserLogInReq has the following members:

String: Username <br/>
String: Password <br/>
String: ClientType <br/>

This is my script so far:

    $request = xmlrpc_encode_request('UserLogInReq', array("UserName" => '$username',"Password" =>'$password',"ClientType" => ''));

    $context = stream_context_create(array('http' => array(
    'method' => "POST",
    'header' => "Content-Type: text/xml",
    'content' => $request
    )));

    $file = file_get_contents("http://someserver/somepage.ashx", false, $context);

    $response = xmlrpc_decode($file);

    if ($response && xmlrpc_is_fault($response)) {
      trigger_error("xmlrpc: $response[faultString] ($response[faultCode])");
    } else {
      print_r($response);
    }

When I navigate to my web-service page, at somepage.ashx, this method is listed, with all of those members. However, when I run this script, I am getting:

    Notice: unsupported method called: UserLogInReq (0)

All the help I could find is somehow un-related to a generic xml-rpc hookup/call. 

Is this a permissions problem with the web-service?
What am I doing wrong?

Thanks!