So the problem here is that for some reason one of the myfaces widgets is holding a hard reference to the SFSB. I'm really not sure why it is doing that. Are you using some funny myfaces widgets, or just the standard JSF controls? Did you put your SFSB in PAGE scope? Anyway, the relevant change b/w 1.0.1 and 1.1 is that we introduced client-side interceptors by using CGLIB proxies for all session beans (this is a nice feature). But as this bug reports: http://jira.jboss.com/jira/browse/JBSEAM-332 the CGLIB proxies are not serializable. Now, I actually happen to know how to make CGLIB proxies serialize correctly, since I have done it before in Hibernate. So I just need to get around to fixing this :-) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3977953#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...