did you change your ejb-jar.xml file at all?
no. I have just deployed the same ear like the one which works on the normal Jboss4 (without EJB3 feature).
We got the same error. When we run our applocation with "JBoss 4.0.4 GA + EJB3", the entity bean failed to deploy. Then we got the EJB name not bound JNDI look up error. During the JBoss start up, we see only the session beans got deployed, but not the EJB2 entity beans.
We have to change the ejb-jar.xml to the following to avoid the paser error.