I am wondering why when I hit the button twice on the page below and then hit the browser back button there is an error, but when I change combinescripts="true" it doesn't cause an error.
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication1.WebForm1" %><%@ Register TagPrefix="ajaxToolkit" Namespace="AjaxControlToolkit" Assembly="AjaxControlToolkit" %><!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml"><head runat="server"><title></title></head><body><form id="form1" runat="server"><ajaxToolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server" ScriptMode="Release" CombineScripts="false"></ajaxToolkit:ToolkitScriptManager><div><asp:Button ID="Button2" runat="server" Text="Button" /></div></form></body></html>