I am developing a web application in which i m facing problem of dropdown residing inside user control is not updated.

Overview of Entire Problem.
As per my and client's requirement:
I've created two user control.
One user control having a drop down.
Another user control having few no of controls and its event.

Both user control i've used in my one web page twice.

For partial postback use following AjaxSettings.

 <telerik:RadAjaxManager ID="RadAjaxManager1" DefaultLoadingPanelID="RadAjaxLoadingPanel1"
        runat="server">
  <AjaxSettings>
 <telerik:AjaxSetting AjaxControlID="btnSave">
                <UpdatedControls>
                    <telerik:AjaxUpdatedControl ControlID="FilterDropDown" />
                    <telerik:AjaxUpdatedControl ControlID="FilterDropDownGridContact" />
                </UpdatedControls>
            </telerik:AjaxSetting>
</AjaxSettings>
    </telerik:RadAjaxManager>
    <telerik:RadAjaxLoadingPanel ID="RadAjaxLoadingPanel1" runat="server">
    </telerik:RadAjaxLoadingPanel>

Now concentrate here,
btnSave is asp server side button residing inside in second user control.
And as I told both user control i've used in my same page twice.
FilterDropDown and FilterDropDownGridContact is two user control.(having only a drop down)
Now when I click on btnSave of first user control event fires and as per ajax setting dropdown user control updates.

But, when I click on btnSave of second user control events fires but user control is not updated.

So, Whats issue??

Is there any way, so that i can update ajax setting such as update first user control when respective user control's btnSave fires and so on.