If you upgrade from Microsoft ASP.NET AJAX Extensions 1.0 to 3.5, and you have a TabContainer inside an update panel, like this: < asp : UpdatePanel ID = "UpdatePanel1" runat = "server" > < ContentTemplate > < act : TabContainer runat ...
All about the little-known LoadScriptsBeforeUI setting on the ASP.NET AJAX ScriptManager control, and how it can be used to increase your page load time....