Ajax CollapsiblePanel not working in IE 8 for compatibility mode - asp.net

Question

I am using an ajax collapsiblepanel extender in a webapp (asp.net) designed for IE 6. Currently for making the application compatible with IE 8 i have added a metatag - .
Everything in the application works fine except the collapsible panels using the ajax control.
These panels are always expanded.
Any idea on how to ensure the panels collapse and expand as expected in IE 8.
Note - i have tried changing the css class for collPanel where overflow:hidden is present to display:none but this kept the panel only collapsed.
Code snippet:
<cc1:CollapsiblePanelExtender ID="ColPnlExtAddUser" runat="server" TargetControlID="pnlAddContentUser"
ExpandControlID="pnlAddHeaderUser" CollapseControlID="pnlAddHeaderUser" Collapsed="True"
ImageControlID="ImgBtnAddUser" ExpandedText="(Hide Details...)" CollapsedText="(Show Details...)"
ExpandedImage="~/images/collapse.jpg" CollapsedImage="~/images/expand.jpg" SuppressPostBack="true"
TextLabelID="lblShowUser" BehaviorID="ColPnlExtAddUserBehavior">
</cc1:CollapsiblePanelExtender>
<asp:Panel Style="cursor: pointer" ID="pnlAddHeaderUser" runat="server" CssClass="collHeader">
<div style="padding: 2px; cursor: pointer; vertical-align: middle;">
<div id="Div2" style="float: left;">
<asp:Label ID="labelUserManagement" runat="server" Text="Add User"></asp:Label>
</div>
<div style="float: left; margin-left: 20px;">
<asp:Label ID="lblShowUser" runat="server">(Show Details...)</asp:Label>
</div>
<div style="float: right; vertical-align: middle;">
<asp:ImageButton ID="ImgBtnAddUser" runat="server" ImageUrl="~/images/expand.jpg"
AlternateText="(Show Details...)" />
</div>
</div>
</asp:Panel>
<asp:Panel Style="overflow: hidden" ID="pnlAddContentUser" runat="server" CssClass="collPanel"
Height="0px">
<table id="tblAddUserDetails" width="100%" runat="server">
<tbody>
<tr>
<td align="left">
<a class="labelText">First Name</a>
</td>
<td>
<asp:TextBox ID="firstNameTextbox" runat="Server" MaxLength="20" Width = "48%"></asp:TextBox>
</td>
</tr>
<tr>
<td align="left">
<a class="labelText">Last Name</a>
</td>
<td >
<asp:TextBox ID="lastNameTextbox" runat="Server" MaxLength="20" Width = "48%"></asp:TextBox>
</td>
</tr>
<tr>
<td align="right" colspan="2">
<asp:LinkButton ID="saveUserLinkButton" runat="server" CssClass="btnSimpleSave" OnClick="saveUserLinkButton_Click" >Save</asp:LinkButton>
</td>
</tr>
</tbody>
</table>
</asp:Panel>

Answer 1

ya sometime it support by some version of IE, i suggest you to use Jquery, it is easy and powerful.