Hi I had the same problem. It was because i wasnt persisting the object list. So when it tried to retrieve the list to sort it was null.
In my page I have... @Persist("session") public abstract Collection getItems(); Hope that helps Craig -------------------- m2f -------------------- Sent from www.TapestryForums.com Read this topic online here: <<topic_link>> http://www.tapestryforums.com/viewtopic.php?p=11711#11711 -------------------- m2f --------------------