I am using the ServerSideCallBack to add more nodes to the expanded node on the NodeExpand event. In the event I recursively generate child nodes for the node that is expanded. When I add the child nodes to the node that was expanded it only loads the next level. When I click to expand that level is does not have any more nodes loaded even though when I added child nodes in the NodeExpand event there were more than one level of nodes added. Is there some property I need to set in order for it to load more than one level?