Hi Peter, First of all I would like to answer your question anonymous wrote : are attempting to replace the hsqldb with MySQL? Yes, I waz trying to replace hssqldb with MySQL Also, PU, here doesn't means Public Utilites, in this context PU stands for Persistent Unit (persistent.xml). yes, I tried both, i.e. deploying EJB before and after AS startup. In both cases I got the same result. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4179206#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...