The problem was when the request parameter wasn't passed in via the URL, i.e. when we use the getCustomers() method, which doesn't use that parameter. We were actually expecting a primitive long (I should have checked my capitalization in my previous post), which obviously cannot be made null by Seam when it isn't passed in. We're now expecting a Long object instead, and it works :-) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3957926#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...