Hello,

The below GridPanel has a problem with TabPanel tab switching:

Example.aspx:
<%@ Page Language="C#" %>
<%@ Register Assembly="Coolite.Ext.Web" Namespace="Coolite.Ext.Web" TagPrefix="ext" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"  
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
    protected void Page_Load(object sender, EventArgs e)
    {
        this.Store1.DataSource = new object[]
            {
                new object[] { "Canada", "CA" },
                new object[] { "United States", "USA" }
            };

        this.Store1.DataBind();
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
        <asp:ScriptManager ID="ScriptManager1" runat="server" EnablePartialRendering="True" />
        <ext:ScriptManager ID="ScriptManager2" runat="server" />
        <ExtJS:ViewPort ID="ViewPort" runat="server" Stateful="True">
            <Content>
                <ExtJS:BorderLayout ID="BorderLayout" runat="server" RenderHidden="True">
                    <North Collapsible="True" CollapseMode="Mini" Split="True" MinHeight="43" MaxHeight="173">
                        <ExtJS:Panel ID="North" runat="server" Border="False" Height="173px">
                            <Content>
                                <div class="uber">
                                    <p><a href="Example.aspx">Reload</a></p>
                                

                            </Content>
                        </ExtJS:Panel>
                    </North>
                    <Center Collapsible="True" CollapseMode="Mini" Split="True" MinWidth="825">
                        <ExtJS:Panel ID="Center" runat="server" AutoScroll="True" Border="True">
                            <Content>
                                <ExtJS:TabPanel ID="Tabs1" runat="server" ActiveTab="0" AutoPostBack="True" AutoHeight="True" AutoWidth="True" DeferredRender="True">
                                    <Tabs>
                                        <ExtJS:Tab ID="Tab1" runat="server" Title="Tab1" AutoHeight="True" AutoWidth="True">
                                            <Content>
                                                <ext:Store 
                                                    ID="Store1" 
                                                    runat="server" 
                                                    AutoLoad="True">
                                                    <Reader>
                                                        <ext:ArrayReader ReaderID="Value">
                                                            <Fields>
                                                                <ext:RecordField Name="Name" />
                                                                <ext:RecordField Name="Value" />
                                                            </Fields>
                                                        </ext:ArrayReader>
                                                    </Reader>
                                                </ext:Store>
                                                <ext:GridPanel 
                                                    ID="GridPanel1" 
                                                    runat="server" 
                                                    StoreID="Store1" 
                                                    AutoExpandColumn="Name" 
                                                    AutoHeight="True" 
                                                    Stateful="True" 
                                                    StripeRows="True" 
                                                    Width="400">
                                                    <ColumnModel runat="server">
                                                        <Columns>
                                                            <ext:Column ColumnID="Name" DataIndex="Name" Header="Country" MenuDisabled="True" />
                                                            <ext:Column ColumnID="Value" DataIndex="Value" Header="Value" MenuDisabled="True" Width="255" />
                                                        </Columns>
                                                    </ColumnModel>
                                                </ext:GridPanel>
                                                Tab 1 Selected
                                            </Content>
                                        </ExtJS:Tab>
                                        <ExtJS:Tab ID="Tab2" runat="server" Title="Tab2" AutoHeight="True" AutoWidth="True">
                                            <Content>
                                                Tab 2 Selected
                                            </Content>
                                        </ExtJS:Tab>
                                    </Tabs>
                                </ExtJS:TabPanel>
                            </Content>
                        </ExtJS:Panel>
                    </Center>
                </ExtJS:BorderLayout>
            </Content>
        </ExtJS:ViewPort>
    </form>
</body>
</html>
Replication steps:

1. Load page
2. Notice the GridPanel loads the data (Canada, USA, etc ...) and "Tab 1 Selected" displays
3. Click "Tab 2"
4. Notice "Tab 2 Selected" displays
5. Click "Tab 1"
6. Notice GridPanel disappears and "Tab 1 Selected" displays
7. Click "Tab 2"
8. Notice "Tab 2 Selected" does not display

Fails in IE6 and FF3.0.

Cheers,
Timothy