Ajaxcontoltoolkit tab container not displaying alongisde modal popup extender - asp.net

Question

I'm using VS2010, C#, ASP.NET, I've inserted Ajax Control Toolkit Tab Container which works great, but when I insert a modal popup extender on another panel, tabs do not display! what is going wrong here? How can I have both on them as both are really cool effects
thanks
my tab container:
<cc1:TabContainer runat="server" ID="Tabs" CssClass="visoft__tab_xpie7"
ActiveTabIndex="2" Width="100%" Height="160px">
<cc1:TabPanel runat="server" ID="tab1" HeaderText="برنامه نویسی وب و اتوماسیون">
<HeaderTemplate>
<div >
<asp:Image ID="Image12" BorderStyle="None" runat="server" ImageUrl="~/Images/internet.png" /><br />
وب و اتوماسیون
</div>
</HeaderTemplate>
<ContentTemplate>
<div runat="server" id="divTab1" style="direction:rtl;">
</div>
</ContentTemplate>
<cc1:TabPanel runat="server" ID="tab2" HeaderText="تله متری" >
<HeaderTemplate>
<div >
<asp:Image ID="Image11" BorderStyle="None" runat="server" ImageUrl="~/Images/telemetry.png" /><br />
تله متری
</div>
</HeaderTemplate>
<ContentTemplate>
<div runat="server" id="divTab2" style="direction:rtl;">
</div>
<cc1:TabPanel runat="server" ID="tab3" HeaderText="">
<HeaderTemplate>
<div >
<asp:Image ID="Image10" BorderStyle="None" runat="server" ImageUrl="~/Images/mb.png" /><br />
موبایل، گرافیک، بازی
</div>
</HeaderTemplate>
<ContentTemplate>
<div runat="server" id="divTab3" style="direction:rtl;">
</div>
</ContentTemplate>
<cc1:TabPanel runat="server" ID="TabPanel1" HeaderText="">
<HeaderTemplate>
<div >
<asp:Image ID="Image13" BorderStyle="None" runat="server" ImageUrl="~/Images/flash.png" /><br />
انیمیشن و فلش
</div>
</HeaderTemplate>
<ContentTemplate>
<div runat="server" id="divTab4" style="direction:rtl;">
</div>
</ContentTemplate>
my modal popup extender:
<asp:Panel ID="pnlNews1" runat="server" CssClass="modalPopup" >
<div style="height:100% ; overflow:auto; width: 100%; top:0px; bottom:0px">
<asp:Table ID="Table10" Height="32px" Width="100%" runat="server">
<asp:TableRow HorizontalAlign="Left">
<asp:TableCell>
<asp:ImageButton ID="btnClose1" ToolTip="بستن کادر" runat="server" ImageUrl="~/Images/close.png" />
</asp:TableCell>
</asp:TableRow>
<asp:TableRow HorizontalAlign="Right">
<asp:TableCell>
<asp:Label ID="lblTitle1" runat="server" Font-Names="Tahoma" Text="Label"></asp:Label>
</asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell>
<div runat="server" id="divBody1">
</div>
</asp:TableCell>
</asp:TableRow>
</asp:Table>

Answer 1

I don't know if this helps, but I had a very similar problem. I had some tabs working, then added a modalpopup extender and a panel, and suddendly my tabs dissappeared.
In my case, my modal popup panel's Visible property was set to "False" (which is not really necessary). Like this:
<asp:Panel ID="ModalPopupPanel" runat="server" CssClass="ModalPopupPanel" Visible="False">
When I deleted this property, the Tabs appeared. So it looks now like this:
<asp:Panel ID="ModalPopupPanel" runat="server" CssClass="ModalPopupPanel">
I know you are not setting this property, but maybe you can try something like this to find what is causing the problem?
Sorry I cannot be of any more help.