RadAjaxManager inside UserControl gives error:already associated with the element

[shootermv]

In my scenario i have the RadTreeView on the left and UCDetails on the right. each time some treenode been clicked i want the UCDetails to display the details of item that was clicked on a tree. UCDetails contains RadAjaxManager . At masterPage i put all the contents inside RadAjaxPanel.
code of UC:

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="UCccc.ascx.cs" Inherits="MyWeb.UC.UCccc" %>
<%@ Register TagPrefix="telerik" Namespace="Telerik.Web.UI" Assembly="Telerik.Web.UI" %>
    <telerik:RadAjaxManager ID="RadAjaxManager1" runat="server" >
        <AjaxSettings>
            <telerik:AjaxSetting AjaxControlID="RadGrid1">
                <UpdatedControls>
                    <telerik:AjaxUpdatedControl ControlID="RadGrid1" />
                </UpdatedControls>
            </telerik:AjaxSetting>
            <telerik:AjaxSetting AjaxControlID="RadAjaxManager1">
                <UpdatedControls>
                    <telerik:AjaxUpdatedControl ControlID="RadGrid1" />
                </UpdatedControls>
            </telerik:AjaxSetting>
        </AjaxSettings>
    </telerik:RadAjaxManager>
toto:<asp:CheckBox ID="RadGrid1" runat="server" />

When page loaded for first time its OK. But after clicking treenode i get error:
Microsoft JScript runtime error: Sys.InvalidOperationException: A control is already associated with the element.

Please Help
thanks forward

[shootermv]

Tanks, i've solved the issue by replacing asp:scriptmanager by RadScriptManager