Inside UpdatePanel AdRotator is not working.....pl hlp

<asp:UpdatePanel ID="upnlDetails2" runat="server">
        <ContentTemplate>
            <table>
                <tr>
                    <td class="label">
                        <asp:Timer ID="Timer1" runat="server" Interval="5000">
                        </asp:Timer>
                        <asp:AdRotator ID="adrDetails" runat="server" AdvertisementFile="xmlDetails.xml"
                            KeywordFilter="Asp.Net" Target="_blank" Height="100px" Width="100px" ImageUrlField="ImageUrl"
                            NavigateUrlField="NavigateUrl" AlternateTextField="AlternateText" />
                    </td>
                </tr>
            </table>
        </ContentTemplate>
        <Triggers>
            <asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick" />
        </Triggers>
    </asp:UpdatePanel>