I had some help from the trinidad mailing list and did some more debugging. Ultimately it seems the bug is in facelets. They try to determine a component's JSF version by checking if it subclasses UIComponentBase, which fails for Trinidad (which has its own UIXComponentBase). This makes facelets use JSF 1.1 style ValueBindings instead of 1.2's ValueExpressions, which in turn makes Trinidad ignore the ELContext that Seam passes. I created an issue in facelets' issue tracker: https://facelets.dev.java.net/issues/show_bug.cgi?id=239 What could be a better way to check for the version? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4071742#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...