Yep, migrating is a difficult and special thing with EJB2.
So you will find a lot of issues where two app server are different if you are a bit beside the spec or where the spec is not very clear.
Where do you log the 'startup' message?
Does the bean is created and handle the message if you fill the queue?
Do you have EAP support? Or just evaluate the EAP version?
I would prefer EAP 5.1. Also you might raise a support ticket if you have a support subscription.