Invalid postback or callback argument

[mathieu]

Hi, 

i have the exception:
Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.

Everything is working correctly when i don't use the event OnTabClick.
But I need it and when i try to attach a function to this event (either from the markup or the code behind) i get the exception above.
the hierarchy of the markup is as follow : 
asp:panel
  RadAjaxPanel
    RadTabStrip
RadMultiPage
 div
  table
    tr
  td
             RadAjaxPanel
               RadTabStrip
          RadMultiPage

The markup is :

<telerik:RadTabStrip runat="server" ID="TabStrip" MultiPageID="MultiPage" OnTabClick="TabStrip_TabClick"
    SelectedIndex="0" Font-Size="Smaller" Orientation="VerticalLeft">
    <Tabs>
        <telerik:RadTab Text="Note de calcul"     PageViewID="rpv_noteCalcul"    Value="noteCalcul" Selected="True" />
        <telerik:RadTab Text="Crédits" PageViewID="rpv_Credits"    Value="Credits" />
        <telerik:RadTab Text="Paiements"      PageViewID="rpv_Paiements"  Value="Paiements" />
        <telerik:RadTab Text="Distribution"   PageViewID="rpv_Distribution" Value="Distribution" />
    </Tabs>
</telerik:RadTabStrip>

when i tried to attach the event from the code behind i did :  (when i did i remove the argument OnTabClick from the markup)

protected void Page_Init(Object sender, EventArgs e)
{
    TabStrip.TabClick += new RadTabStripEventHandler(TabStrip_TabClick);
}

the function that i need to call:

protected void TabStrip_TabClick(object sender, RadTabStripEventArgs e)
{

}

Hope you can help me 

Thank you