I'm using multiple treeviews on a page, bound to WCF services on a NTLM authenticated website. If more than a single treeview is requesting data to come from the webservice only the first works and the others immediately fail. On the server side for some reason it's because the subsequent requests are coming in unauthenticated. However if I put in a setTimeout()s on the extra treeviews so they load sequentially there's no errors. Instead of relying on an uncertain setTimeout()s, is there any way to have a treeview retry it's dataload on failure, or do you have any ideas on how to get multiple simultaneous requests to NTLM authenticated wcf services to work?