jar:mywar.war!/WEB-INF/classes/ should be a valid point a valid input See Carlo's comment " I've changed the way EJB 3 submits the persistence root url to Hibernate. See http://viewvc.jboss.org/cgi-bin/viewvc.cgi/jbossas?view=rev&revision=67653 . "
http://www.jboss.com/index.html?module=bb&op=viewtopic&t=124223&postdays=0&postorder=desc&start=0
2007-12-03 17:03:48,328 DEBUG [org.hibernate.ejb.packaging.JarVisitor:217] Searching mapped entities in jar/par: jar:file:/tmp/nestedjar51134.tmp!/WEB-INF/classes/
C'est tout.
2007-12-03 17:03:48,328 DEBUG [org.hibernate.ejb.packaging.JarVisitor:217] Searching mapped entities in jar/par: jar:file:/tmp/nestedjar51134.tmp!/WEB-INF/classes/
C'est tout.