The problem is that the final version of the EJB3 API is dependent on Java 5 constructs. For example, javax.ejb.SessionContext.getBusinessObject() returns a Generic. So we cannot compile some client classes using JDK1.4. The earlier versions of the specification were not dependent on Java 5 constructs, so we were able to support JDK1.4 clients in our earlier release (e.g. EJB3 RC6). View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4080585#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...