Doh! That's what I get for having the seam 1.0.1 beta _and_ the seam 1.1.0 beta on my machine at the same time. My bad. However, after succesfully deploying the correct booking application on JBoss 4.0.5.GA I was able to reproduce my error in the booking application with one caveat. Both apps (mine and the booking) will only throw the exception when STATE_SAVING_METHOD is set to server. Sorry for the earlier confusion. Any ideas? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3981866#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...