PersistenceUnit null not found

[Michael Simons]

Hello,

I've declared a persistence-unit named "AtlantisWest" in my persistence.xml, 
that I reference in
my bean by
    @PersistenceContext(name="AtlantisWest", 
type=PersistenceContextType.EXTENDED)
    protected EntityManager     entityManager;

Can anybody please tell me what might cause the following exception when 
deploying my bean:

Caused by: org.apache.openejb.OpenEJBException: Error building bean 
'MapAuxiliaryServiceBw'.
Exception: class org.apache.openejb.OpenEJBException: PersistenceU
nit 'null' not found for EXTENDED ref 'AtlantisWest': PersistenceUnit 'null' 
not found for
EXTENDED ref 'AtlantisWest'
        at 
org.apache.openejb.assembler.classic.EjbJarBuilder.build(EjbJarBuilder.java:64)
        at 
org.apache.openejb.assembler.classic.Assembler.createApplication(Assembler.java:489)
        ... 52 more
Caused by: org.apache.openejb.OpenEJBException: PersistenceUnit 'null' not 
found for EXTENDED
ref 'AtlantisWest'
        at
org.apache.openejb.assembler.classic.EnterpriseBeanBuilder.build(EnterpriseBeanBuilder.java:198)
        at 
org.apache.openejb.assembler.classic.EjbJarBuilder.build(EjbJarBuilder.java:52)


Kind Regards, Michael