Following your comments I made a few more tests using the same JBoss installation and Seam 1.1.6: Everything workd fine. There are a couple differences between Registration versions (a couple tags missing and declaring Log as static) that are not related with the validation problem. The main problem is that jboss-seam-registration.war generated by version 1.1.0 does not contain jboss-seam-ui.jar in WEB-INF directoy. Thanks a lot gentlemen! View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4022665#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...