I'm getting an javax.naming.NameNotFoundException when invoking @PersistenceContext(unitName= inside a bean.

The persistence.xml using is defined as follows:

<persistence-unit name="-persistence-pu">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
         <jta-data-source>java:jboss/datasources/ExampleDS</jta-data-source>
         <class>x.x.x.persistence.entities.RpEntity</class>
        <exclude-unlisted-classes>true</exclude-unlisted-classes>
        <properties>
            <property name="eclipselink.target-database" value="oracle"/>
            <property name="eclipselink.target-server" value="JBoss"/>
            <property name="eclipselink.weaving" value="false"/>
            <property name="eclipselink.logging.level" value="FINEST"/>          
        </properties>
    </persistence-unit>

The bean is defined as the following:

@Repository("rptDefDao")
public class RptDAOBean implements RpDAO {

 
    @PersistenceContext(unitName="persistence-pu")
    private EntityManager em;

This is a spring 3.04 app.

Does anyone have any ideas.