EJB shows "UnsatisfiedReferenceImpl" in VA JNDI Registry

I have a ejb that I am using in J2EE and non-J2EE (portal application). The EJB seems to work fine in both cases [local and remote].

When I use VA's JNDI browser (Visual Administrator->JNDI Registry) and drill down to Bean there are two entries "Class Name" and "Object Value".

Values are

"Class Name" ==> "com.sap.engine.services.jndi.persistent.UnsatisfiedReferenceImpl"

"Object Value" ==> "com.sap.engine.services.jndi.persistent.UnsatisfiedReferenceImpl@19beb53 Returned because an Exception occured in deserialization process:[java.lang.ClassCaseException]

Is this a problem in bean implementation?

How to fix this problem?

why is bean working (or is not)?.

Thanks