When selecting "Jboss EJB3 Libraries" in Eclipse-Project Build-path settings, while using Jboss 4.2CR2, the project cannot be build, cause there are build-path errors, cause of jboss-ide is missing the "jboss-ejb3x.jar".
Reason: since Jboss 4.2CR2 the jboss-ejb3x.jar isn't anymore in the $SERVER_HOME/server/default/deploy/ejb3.deployer directory. It's now located in the $SERVER_HOME/server/default/lib directory.