Incorrect behaviour with @WebParam(header = true, mode = IN)

@Stateless
@WebService(name = "MyEchoService", targetNamespace = "urn:echo")
public class MyEchoService {
	
	@WebResult(name = "result")
	public String echo(
			@WebParam(name = "message") String message,
			@WebParam(name = "paramIn", mode = Mode.IN, header = true) Holder<String> paramIn,
			@WebParam(name = "paramOut", mode = Mode.OUT, header = true) Holder<String> paramOut) {
		paramOut.value = "got paramIn " + paramIn.value;
		return "echo " + message;
	}
}

<wsdl:operation name="echo">
	<soap:operation soapAction="" style="document"/>
	<wsdl:input name="echo">
		<soap:header message="tns:echo" part="paramIn" use="literal"></soap:header>
		<soap:body parts="parameters" use="literal"/>
	</wsdl:input>
	<wsdl:output name="echoResponse">
		<soap:header message="tns:echoResponse" part="paramIn" use="literal"></soap:header>
		<soap:header message="tns:echoResponse" part="paramOut" use="literal"></soap:header>
		<soap:body parts="result" use="literal"/>
	</wsdl:output>
</wsdl:operation>

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:urn="urn:echo">
   <soapenv:Header>
      <urn:paramIn>fred</urn:paramIn>
   </soapenv:Header>
   <soapenv:Body>
      <urn:echo>
         <urn:message>hello world!</urn:message>
      </urn:echo>
   </soapenv:Body>
</soapenv:Envelope>

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
   <soap:Header>
      <paramIn xmlns="urn:echo">fred</paramIn>
      <paramOut xmlns="urn:echo">got paramIn fred</paramOut>
   </soap:Header>
   <soap:Body>
      <echoResponse xmlns="urn:echo">
         <result>echo hello world!</result>
      </echoResponse>
   </soap:Body>
</soap:Envelope>

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:urn="urn:echo">
   <soapenv:Body>
      <urn:echo>
         <urn:message>hello world!</urn:message>
      </urn:echo>
   </soapenv:Body>
</soapenv:Envelope>

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
   <soap:Header>
      <paramOut xmlns="urn:echo">got paramIn null</paramOut>
   </soap:Header>
   <soap:Body>
      <echoResponse xmlns="urn:echo">
         <result>echo hello world!</result>
      </echoResponse>
      <paramIn xsi:nil="true" xmlns="urn:echo" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/>
   </soap:Body>
</soap:Envelope>