How do I get Groovy and JAXB to play nice together

I am trying to get JAXB to work with a groovy class of mine, however, it appears it doesn't work but the java version does. Here is the code...

Here are the Scenarios:

If 2 and 3 are uncommented it works fine.

If 1 and 4 are uncommented I get:

 com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException:
       2 counts of IllegalAnnotationExceptions
 groovy.lang.MetaClass is an interface, and JAXB can't handle interfaces.

If 1 and 5 are uncommented I get:

  javax.xml.bind.JAXBException: class org.oclc.presentations.simplejaxb.PlayerGroovy
        nor any of its super class is known to this context.

Any ideas?

Java:

    import javax.xml.bind.annotation.XmlRootElement;

    @XmlRootElement
    public class Player {
    }

Groovy:

    import javax.xml.bind.annotation.XmlRootElement

    @XmlRootElement
    public class PlayerGroovy {
    }

Test:

    import org.junit.Test
    import javax.xml.bind.JAXBContext
    import javax.xml.bind.Marshaller
    import org.junit.Assert

    class PlayerTest {
        @Test
        public void testJaXB(){
            //1 PlayerGroovy player = new PlayerGroovy()
            //2 Player player = new Player()
            StringWriter writer = new StringWriter();
            //3 JAXBContext context = JAXBContext.newInstance(Player.class);
            //4 JAXBContext context = JAXBContext.newInstance(PlayerGroovy.class);
            //5 JAXBContext context = JAXBContext.newInstance(PlayerGroovy.getClass());
            Marshaller m = context.createMarshaller();
            m.marshal(player, writer);
            println(writer)
            Assert.assertTrue(true)
        }
    }