Hi. I had the same problem. After long googling i found the answer here: http://wiki.jboss.org/wiki/Wiki.jsp?page=CommonHurdlesAndDifficultiesYouM... There are two possible error scenaries: 1. You packaged the same class file twice in the same EAR (in two different JARs for example) 2. You specified incomplete JNDI name at lookup (forgot /local or /remote) Solution to the first scenario is to either enable call by value in the conf file naming-service.xml or repackage your ear without duplicates You don't have to be genious to figure out solution to the second scenario ;) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3975633#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...