The problem was that there are 2 sets of hibernate jars that are build via seam-gen. A set in lib and a single other one in lib/test. Eclipse was using the ones in lib and Ant had the one in lib/test higher in the classpath. On removing the one in lib/test, all works great. Anyone know the reasoning for 2 sets of hibernate jars? Thanks, Sean View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4103447#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...