I am stumped. Based on the output you sent me, it should work. The C:\jboss-4.0.4.CR2\client\jbossall-client.jar, which contains the org.jnp.interfaces.NamingContextFactory is in the class path, so there should be no problem in finding and loading that class. It is almost as if, suddenly, another class loader was invoked, one which did not know about the classpath. All I can suggest is to try it from the command line (to eliminate Eclipse messing something up), and to also try a simpler program that only looks up the EJB in jndi (you should be able to get by with a much shorter classpath and thus be able to more easily run it manually from the command line). View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3994472#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...