mock-server simple mock not working with XML in the body

I have a mock server using: http://ift.tt/1iJmeii

That server has two different rules for the POST that hits it. Here is the java code:

package mockserver.poc;

import static java.util.concurrent.TimeUnit.SECONDS;
import static org.mockserver.model.HttpRequest.request;
import static org.mockserver.model.HttpResponse.response;
import static org.mockserver.model.StringBody.regex;

import org.mockserver.client.server.MockServerClient;
import org.mockserver.mockserver.MockServer;
import org.mockserver.model.Delay;

public class MockServerPoc {

    public static void main(String[] args) {
        MockServer mockServer = new MockServer(8888);
        System.out.println("Running:" + mockServer.isRunning());

        MockServerClient mockServerClient = new MockServerClient("10.189.225.196", 8888);

        mockServerClient.when(
                request()
                        .withMethod("POST")
                        .withPath("/something1")
                        .withBody(regex("SubscriberA"))
        )
        .respond(
                response()
                        .withBody("<xml>\n something1 ok \n<xml>")
                        .withDelay(new Delay(SECONDS, 1))
        );

        mockServerClient.when(
                request()
                        .withMethod("POST")
                        .withPath("/something1")
                        .withBody(regex("SubscriberB"))
        )
        .respond(
                response()
                        .withBody("<xml>\n something2 ok \n<xml>")
                        .withDelay(new Delay(SECONDS, 1))
        );
    }
}

The problem with that code is that, using SOAPUI, if I try to hit it with the following XML:

<?xml version="1.0" encoding="UTF-8"?>
<ns2:Envelope xmlns:ns2="http://ift.tt/sVJIaE">
   <ns2:Body>
     <objectclass>SubscriberA</objectclass>
   </ns2:Body>
</ns2:Envelope>

I don't get the expected result

<xml>\n something1 ok \n<xml>

If the body is just SubscriberA, it works fine, but if it is the entire XML, it simple doesn't work.

Am I doing wrong something wrong?