JavaEE 5 annotated Webservice-EJB fails

A JavaEE 5 annotated Webservice-EJB (works with JBoss AS 5.1, Glassfish 2.1 and Websphere 7) fails with:

Caused by: java.lang.LinkageError: loader constraint violation in interface itable initialization: when resolving method "$Proxy280.setElementType(Ljavax/xml/namespace/QName;)V" the class loader (instance of org/jboss/classloader/spi/base/BaseClassLoader) of the current class, $Proxy280, and the class loader (instance of org/jboss/classloader/spi/base/BaseClassLoader) for interface javax/wsdl/extensions/ExtensibilityElement have different Class objects for the type javax/xml/namespace/QName used in the signature
at java.lang.Class.getDeclaredConstructors0(Native Method) [:1.6.0_24]
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2389) [:1.6.0_24]
at java.lang.Class.getConstructor0(Class.java:2699) [:1.6.0_24]
at java.lang.Class.getConstructor(Class.java:1657) [:1.6.0_24]
at java.lang.reflect.Proxy.newProxyInstance(Proxy.java:587) [:1.6.0_24]
at org.apache.cxf.tools.util.SOAPBindingUtil.getProxy(SOAPBindingUtil.java:87) [:2.3.1]
at org.apache.cxf.tools.util.SOAPBindingUtil.getSoapBinding(SOAPBindingUtil.java:274) [:2.3.1]
at org.apache.cxf.tools.util.SOAPBindingUtil.createSoapBinding(SOAPBindingUtil.java:426) [:2.3.1]
at org.apache.cxf.binding.soap.SoapBindingFactory.createSoapBinding(SoapBindingFactory.java:213) [:2.3.1]
at org.apache.cxf.binding.soap.SoapBindingFactory.createBindingInfo(SoapBindingFactory.java:198) [:2.3.1]
at org.apache.cxf.binding.AbstractBindingFactory.createBindingInfo(AbstractBindingFactory.java:97) [:2.3.1]
at org.apache.cxf.frontend.AbstractWSDLBasedEndpointFactory.createBindingInfo(AbstractWSDLBasedEndpointFactory.java:339) [:2.3.1]
at org.apache.cxf.jaxws.JaxWsServerFactoryBean.createBindingInfo(JaxWsServerFactoryBean.java:166) [:2.3.1]
at org.apache.cxf.frontend.AbstractWSDLBasedEndpointFactory.createEndpointInfo(AbstractWSDLBasedEndpointFactory.java:251) [:2.3.1]
at org.apache.cxf.frontend.AbstractWSDLBasedEndpointFactory.createEndpoint(AbstractWSDLBasedEndpointFactory.java:147) [:2.3.1]
at org.apache.cxf.frontend.ServerFactoryBean.create(ServerFactoryBean.java:148) [:2.3.1]
at org.apache.cxf.jaxws.JaxWsServerFactoryBean.create(JaxWsServerFactoryBean.java:183) [:2.3.1]
at org.apache.cxf.jaxws.EndpointImpl.getServer(EndpointImpl.java:407) [:2.3.1]
at org.apache.cxf.jaxws.EndpointImpl.doPublish(EndpointImpl.java:314) [:2.3.1]
at org.jboss.wsf.stack.cxf.deployment.EndpointImpl.doPublish(EndpointImpl.java:62) [:3.4.1.GA]
at org.apache.cxf.jaxws.EndpointImpl.publish(EndpointImpl.java:238) [:2.3.1]
at org.apache.cxf.jaxws.EndpointImpl.publish(EndpointImpl.java:481) [:2.3.1]
at org.jboss.wsf.stack.cxf.configuration.NonSpringBusHolder.configure(NonSpringBusHolder.java:112) [:3.4.1.GA]
at org.jboss.wsf.stack.cxf.deployment.aspect.BusDeploymentAspect.start(BusDeploymentAspect.java:110) [:3.4.1.GA]
at org.jboss.webservices.integration.deployers.WSDeploymentAspectDeployer.internalDeploy(WSDeploymentAspectDeployer.java:123) [:6.0.0.Final]
at org.jboss.deployers.spi.deployer.helpers.AbstractRealDeployer.deploy(AbstractRealDeployer.java:55) [:2.2.0.GA]
at org.jboss.deployers.plugins.deployers.DeployerWrapper.deploy(DeployerWrapper.java:179) [:2.2.0.GA]
... 44 more

Webservice-EJB:
@Stateless
@WebService(name = "TestReportService",
serviceName = "AsmsWebservice",
targetNamespace= "http://webservice.asms.airsight.de")
@SOAPBinding(style = SOAPBinding.Style.DOCUMENT,
use = SOAPBinding.Use.LITERAL,
parameterStyle = SOAPBinding.ParameterStyle.WRAPPED)
public class TestReportService implements TestReportServiceRemote, Serializable {
@PersistenceContext
private EntityManager em;

@WebMethod(action = "createFullTestReport")
@WebResult(name="successful")
public boolean createFullTestReport(
@WebParam(name="name") String name,
@WebParam(name="id") Long id,
@WebParam(name="feedback") Boolean feedback,
@WebParam(name="altitude") Double altitude)

{ return true; }

}

@Remote
public interface TestReportServiceRemote {
public boolean createFullTestReport(String name, Long id, Boolean feedback, Double altitude);
}

standard-jaxws-endpoint-config.xml:
<jaxws-config xmlns="urn:jboss:jaxws-config:2.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:javaee="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="urn:jboss:jaxws-config:2.0 jaxws-config_2_0.xsd">
<endpoint-config>
<config-name>Seam WebService Endpoint</config-name>
<pre-handler-chains>
<javaee:handler-chain>
<javaee:protocol-bindings>##SOAP11_HTTP</javaee:protocol-bindings>
<javaee:handler>
<javaee:handler-name>SOAP Request Handler</javaee:handler-name>
<javaee:handler-class>org.jboss.seam.webservice.SOAPRequestHandler</javaee:handler-class>
</javaee:handler>
</javaee:handler-chain>
</pre-handler-chains>
</endpoint-config>
</jaxws-config>