Telerik and lightBox

In my master page I have RadScriptManager and AjaxControlToolKit which work fine together. However on one of my pages I had LightBoxScriptManager.

I tried to remove LightBoxScriptManager and in my master page added lightbox script references and at the top reference to the stylesheet. As below:

<telerik:RadScriptManager ID="ScriptManager1" runat="server" ScriptMode="Release" EnableScriptCombine="true" OutputCompression="AutoDetect">            
        <Scripts>             
            <asp:ScriptReference Assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
                Name="MicrosoftAjax.js" Path="Scripts-40412/MicrosoftAjax.js" />
            <asp:ScriptReference Assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
                Name="MicrosoftAjaxWebForms.js" Path="Scripts-40412/MicrosoftAjaxWebForms.js" />                   
            <asp:ScriptReference Path="LightboxNet/js/prototype.js" ScriptMode="Release"/>
            <asp:ScriptReference Path="LightboxNet/js/scriptaculous.js?load=effects,builder" ScriptMode="Release"/>
            <asp:ScriptReference Path="LightboxNet/js/lightbox.js" ScriptMode开发者_运维知识库="Release"/>                    
        </Scripts>                                              
    </telerik:RadScriptManager>  

Unfortunately, the very first page i.e. default.pasx produces an error in IE7: Object doesn't support this property or method

According to viewsource the error is around:

//<![CDATA[
Sys.WebForms.PageRequestManager._initialize('ctl00$ScriptManager1', document.getElementById('aspnetForm'));
Sys.WebForms.PageRequestManager.getInstance()._updateControls([], [], [], 90);
//]]>
</script>  

Lightbox version is v2.02 by Lokesh Dhakar. Any help would be appreciated.

Thank you.

Do you get the same error when you switch the Telerik script manager with asp ScriptManager with similar configuration? If so, the issue is probably influenced by the light box client scripts registration when LightBoxScriptManager is not present.