An addendum: After posting, I tried creating a new bean and it worked fine. I had been noticing startup errors for InstanceAlreadyExistsException, so I wondered if I had been using a cached version of the original bean instead of the latest. So I edited my new bean by adding another method, redeployed it, and it now fails the same way. So I'm thinking that my JSP is wanting to use one definition of my class, and JBoss is supplying a different version of it, thus the ClassCastException (I have a vague recollection that Java is smart enough to see that two classes that coincidentally have the same name can't be cast to one another). So, if that is the case, how do I flush out the old bean definitions? (I already tried deleting everything in the server\default\tmp\deploy directory, but that didn't help) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3957928#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...