I too have been victim to this 'case insensitivity'. Only took me a day to finally find this thread. Spent a lot of time using Google, but it never delivered this. What was maddening for me was I had one jar that worked, because I used Eclipse-export-jar and put the persistence.xml in that, and had another version using Ant and had the case wrong. To make it worse, I used Winzip to view the jars and it shows lower case folders by default. Lesson for me...search the forum! Thanks, Herman Post View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4154014#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...