Problem with using Ajaxloading panel in master page

[sirisha]

I'm getting "Sys.WebForms.PageRequestManager is null or not an object" error when I add an ajaxloadingpanel to the MasterPage
I'm making enablepartialrender of the scriptmanager to false in the master page PageInit(to avoid javascript errors while loading the asp.net report viewer in the child pages).
Not sure if I'm doing anything wrong...below is the code for my master page.

<telerik:RadScriptManager ID="RadScript1" Runat="server">

        </telerik:RadScriptManager>

          

     <telerik:RadAjaxManager ID="RadAjaxManager1" runat="server" 

            DefaultLoadingPanelID="RadAjaxLoadingPanel1" >

        <AjaxSettings>

            <telerik:AjaxSetting AjaxControlID="ViewChooser">

                <UpdatedControls>

                   <telerik:AjaxUpdatedControl ControlID="ViewChooser" 

                      />

                    <telerik:AjaxUpdatedControl ControlID="ContentPlaceHolder1" />

                </UpdatedControls>

            </telerik:AjaxSetting>

             

        </AjaxSettings>

    </telerik:RadAjaxManager>

        <div class="tabStripHeader">

            <asp:Panel runat="server" ID="ViewChooserWrapper">

              

                <telerik:RadTabStrip ID="ViewChooser" runat="server" Height="21px" 

                SelectedIndex="0" Width="100%" 

                ShowBaseLine="True">

                    <Tabs>

                        <telerik:RadTab runat="server" Text="Alerts" Value="alerts.ascx" ImageUrl="~/Images/s.png" 

                        CssClass="AlertsTab" SelectedCssClass="AlertsTabSelected" NavigateUrl="~/Aspx/Alerts/Alerts.aspx"></telerik:RadTab>

                        <telerik:RadTab runat="server" Text="Orders" Value="Orders.ascx" ImageUrl="~/Images/s.png" 

                        CssClass="OrdersTab" SelectedCssClass="OrdersTabSelected" NavigateUrl="~/Aspx/Orders/Orders.aspx"></telerik:RadTab>

                        <telerik:RadTab runat="server" Text="Commissions" ImageUrl="~/Images/s.png" 

                        CssClass="ReportsTab" SelectedCssClass="ReportsTabSelected"  NavigateUrl="~/Aspx/CommReports.aspx">

                        </telerik:RadTab>

  

                        <telerik:RadTab runat="server" Text="Copy" Value="Copy.ascx" ImageUrl="~/Images/s.png" 

                         CssClass="CopyTab" SelectedCssClass="CopyTabSelected" Visible="false"></telerik:RadTab>

                        <telerik:RadTab runat="server" Text="Credit" NavigateUrl="~/Aspx/Credit.aspx" ImageUrl="~/Images/s.png" 

                         CssClass="CreditTab" SelectedCssClass="CreditTabSelected"></telerik:RadTab>

                        <telerik:RadTab runat="server" Text="Clients" Value="Clients.ascx" ImageUrl="~/Images/s.png"  Visible="false"

                         CssClass="ClientTab" SelectedCssClass="ClientTabSelected"></telerik:RadTab>

                    </Tabs>

  

                </telerik:RadTabStrip>

            </asp:Panel>

        </div>

        <div>

            <asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">

              

            </asp:ContentPlaceHolder>

            <asp:ContentPlaceHolder ID="ContentPlaceHolder2" runat="server">

              

            </asp:ContentPlaceHolder>

            <telerik:RadAjaxLoadingPanel ID="RadAjaxLoadingPanel1" runat="server" IsSticky="true">

            </telerik:RadAjaxLoadingPanel>

        </div>