Eu preciso formatar / construir um pedido para este "serviço" SOAP:http://api.notificationmessaging.com/NMSOAP/NotificationService?wsdl

Idealmente, eu gostaria de usar a classe PHP SOAP nativa, mas estou começando a me perguntar se essa classe não é a causa dos meus problemas.

O manual fornece este exemplo:

    <soapenv:Body>
        <api:sendObject>
            <arg0>
                <content>
                    <entry>
                        <key>1</key>
                        <value>
                        <![CDATA[
                        <table width="600">
                        <tr>
                        <td>
                        <font size="2" face="Arial">Our powerful algorithms already
                        found a matching profile that matches your criteria:
                        <br>Celina72&nbsp;</font>
                        <img src="http://mypath/to/my/image.gif" width="50"
                        height="50" border="0" />
                        </td>]]></value>
                    </entry>
                </content>
                <dyn>
                    <entry>
                        <key>FIRSTNAME</key>
                        <value>john</value>
                    </entry>
                </dyn>
                <email>[email protected]</email>
                <encrypt>BdX7CqkmjSivyBgIcZoN4sPVLkx7FaXGiwsO</encrypt>
                <notificationId>6464</notificationId>
                <random>985A8B992601985A</random>
                <senddate>2008-12-12T00:00:00</senddate>
                <synchrotype>NOTHING</synchrotype>
                <uidkey>EMAIL</uidkey>
            </arg0>
        </api:sendObject>
    </soapenv:Body>
</soapenv:Envelope>

Aqui está o lixo que minha solicitação PHP produz (de __getLastRequest ())

<?xml version="1.0" encoding="UTF-8"?>
    <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="http://api.service.nsapi.emailvision.com/" xmlns:ns2="http://xml.apache.org/xml-soap">
        <SOAP-ENV:Body>
            <ns1:sendObject/>
            <param1>AAAAAAAAAAAAAAAAAAAAAAAAAAA</param1>
            <param2>123456789</param2>
            <param3>BBBBBBBBBBBB</param3>
            <param4>2013-09-09T00:00:00</param4>
            <param5>NOTHING</param5>
            <param6>EMAIL</param6>
            <param7>
                <ns2:Map>
                    <item>
                        <key>2</key>
                        <value>TEST</value>
                    </item>
                </ns2:Map>
            </param7>
            <param8>
                <ns2:Map>
                <item>
                    <key>FIRSTNAME</key>
                    <value>John</value>
                </item>
            </ns2:Map>
            <ns2:Map>
                <item>
                    <key>LASTNAME</key>
                    <value>Smith</value>
                </item>
            </ns2:Map>
        </param8>
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

Minha chamada:

$client = new SoapClient('http://api.notificationmessaging.com/NMSOAP/NotificationService?wsdl', array( 'trace' => 1, 'exceptions' => 0 ) );

Os params são assim (modificados com dados fictícios):

$email = '[email protected]';
$encrypt = 'AAAAAAAAAAAAAAAAAAAAAAAAAAA';
$notification_id = 123456789;
$random = 'BBBBBBBBBBBB';
$senddate = '2013-09-09T00:00:00';
$synchrotype = 'NOTHING';
$uidkey = 'EMAIL';

$content = array();
$content[] = array(
    2 => 'TEST'
);

$dyn = array();
$dyn[] = array(
    'FIRSTNAME' => 'John'
);
$dyn[] = array(
    'LASTNAME' => 'Smith'
);

$params = array(
    'email' => $email,
    'encrypt' => $encrypt,
    'notificationId' => $notification_id,
    'random' => $random,
    'senddate' => $senddate,
    'synchrotype' => $synchrotype,
    'uidkey' => $uidkey,
    'content' => $content,
    'dyn' => $dyn
);

Eu então executo o pedido assim:

$res = $client->__soapCall( 'sendObject', array( $email, $encrypt, $notification_id, $random, $senddate, $synchrotype, $uidkey, $content, $dyn ) );

Por que o PHP não consegue formatar meu pedido corretamente? Existe uma abordagem mais direta onde eu poderia escrever o XML "à mão" e depois publicá-lo usando cURL?