Hi,can you tell me  how to solve the issue except "<WindowSettings AllowClose="No" >"

I have used .netframework4.0+VS2010.
When the demo runs,It causes js wrong,too.
Please check the attach file.

ISRes.axd?D/WebDesktopManager.js/307200311    ; 
   if (btnEl) { if (btnEl ==v56542 ||btnEl.contains(v56542)) 

The things I have done:
1、I have used VS2008,VS2010 Tested,It causes wrong,too.
2、I have used other people's Computer Tested,It causes wrong,too.

I find that it caused wrong On IE(it runs normal on FF)
the wrong Information:
   ISRes.axd?D/WebDesktopManager.js/307200311    ; 
   if (btnEl) { if (btnEl ==v56542 ||btnEl.contains(v56542))

Please Test the Demo on IE8.0.

When  you close the 'X',It will cause js wrong,

(I am sure it causes Js wrong By UpdatePannal,when I remove       
<asp:ScriptManager ID="ScriptManager2" runat="server" />
        <asp:UpdatePanel ID="UpdatePanel2" runat="server">
            <ContentTemplate>  ......      </ContentTemplate>
        </asp:UpdatePanel>  it will not cause js wrong.)

thank you

I am Sorry your demo works wrong ,too.
Anyway,I use your  standard Demo ,it works wrong on ff,but it works right on IE8.0
please see the picture below.
My Environment:
WinServer 2003 Sp2
Visual 2008
FireFox3.6.10