I am finding some strange behavior with the PopupControlExtender when it is located inside an UpdatePanel.  The events raised by the children inside the popup are not being fired.  In the example I have pasted below, when I click "Add Employee", I want the AddEmployee_Click event to fire; but it does not -- UNLESS I remove the outer UpdatePanel surrounding the entire html block (as shown below).  However, I want to repeate this block of code repeatedly (in a user control) and would prefer the entire thing is not completely sent back to the server.  Does the popup control not support being inside of a UpdatePanel?

Here is the HTML code:

                <asp:UpdatePanel ID="MainUpdatePanel" runat="server" ChildrenAsTriggers="true">
    <ContentTemplate>
        <table border="0">
            <tr>
                <td>
                    <asp:ListBox ID="MainEmployeeList" runat="server" SelectionMode="multiple" Rows="1">
                        <asp:ListItem Value="10" Text="1name0" />
                    </asp:ListBox >
                </td>
                <td> 
                    <asp:LinkButton ID="AddEmployee" runat="server" Text="Add" OnClientClick="return false;" /> |
                    <asp:LinkButton ID="RemoveEmployee" runat="server" Text="Remove Selected" OnClick="RemoveEmployee_Click" /> |
                    <asp:LinkButton ID="ViewEmployee" runat="server" Text="View Details" OnClientClick="return false" />                
                </td>
            </tr>  
        </table>
        <asp:Panel ID="EmployeeContainer" runat="server" class="modalPopup">          
            <asp:UpdatePanel ID="employeePanel" runat="server" ChildrenAsTriggers="true" >
                <ContentTemplate>                    
                    <table>
                        <tr>
                            <td>Branch:</td>
                            <td>
                                <table border="0" cellpadding="0" cellspacing="0">
                                    <tr>
                                        <td>
                                             <asp:DropDownList ID="BranchList" runat="server" AutoPostBack="true" OnSelectedIndexChanged="BranchList_SelectedIndexChanged">
                                                <asp:ListItem Value="1" Text="This Branch" />
                                                <asp:ListItem Value="2" Text="Branch 2" />
                                                <asp:ListItem Value="3" Text="Branch 3" />
                                            </asp:DropDownList>
                                        </td>
                                        <td>
                                             <asp:UpdateProgress id="progress" runat="server" DisplayAfter="0">
                                                <ProgressTemplate>
                                                     Loading...
                                                </ProgressTemplate>
                                           </asp:UpdateProgress>
                                        </td>
                                    </tr>
                                </table>
                            </td>
                        </tr>
                        <tr>
                            <td></td>
                            <td><asp:ListBox ID="AddEmployeeList" runat="server" SelectionMode="multiple" Rows="15" /></td>
                        </tr>
                        <tr>
                        <td></td>
                        <td><asp:Button ID="AddEmployeeAction" runat="server" Text="Add" OnClick="AddEmployeeAction_Click" />
                            <asp:Button ID="CancelEmployeeAction" runat="server" Text="Cancel (does not work)" OnClientClick="$object('ModalDialog_AddEmployee').hidePopup();" /></td>
                        </tr>
                    </table>
                </ContentTemplate>
            </asp:UpdatePanel>
        </asp:Panel>
        <cc1:PopupControlExtender ID="ModalDialog" Position="Right" runat="server" OffsetX="5"
                 TargetControlID="AddEmployee" PopupControlID="EmployeeContainer" />
    </ContentTemplate>
</asp:UpdatePanel>

And here is the code behind:

protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
             RenderList("1", false);
             ViewEmployee.OnClientClick = string.Format("openEmployeeView({0});", MainEmployeeList.ClientID);
        }
    }

    protected void BranchList_SelectedIndexChanged(object sender, EventArgs e)
    {
        RenderList(BranchList.SelectedValue, true);
    }

    private void RenderList(string branch, bool showModal)
    {
        AddEmployeeList.Items.Clear();

        for (int i = 0; i < 100; i++)
        {
            ListItem item = new ListItem(string.Format("{0}name{1}", branch, i.ToString()), branch + i.ToString());
            if (!MainEmployeeList.Items.Contains(item))
                AddEmployeeList.Items.Add(item);
        }

        // on a modal branch refresh, we need to leave the modal open
        //if (showModal)
        //   ModalDialog.Show();
    }
    protected void RemoveEmployee_Click(object sender, EventArgs e)
    {
        // TODO: on remove of employee, need to refresh the hidden list
        // if this employee belongs to the selected branch

        if (null != MainEmployeeList.Items && MainEmployeeList.Items.Count > 0)
        {
            for (int i = 0; i < MainEmployeeList.Items.Count; i++)
            {
                if (MainEmployeeList.Items[i].Selected)
                {
                    MainEmployeeList.Items.RemoveAt(i);
                    i--;
                }
            }
        }
        MainEmployeeList.Rows = MainEmployeeList.Items.Count;
    }
    protected void AddEmployeeAction_Click(object sender, EventArgs e)
    {
        if (null != AddEmployeeList.Items && AddEmployeeList.Items.Count > 0)
        {
            for (int i = 0; i < AddEmployeeList.Items.Count; i++)
            {
                if (AddEmployeeList.Items[i].Selected)
                {
                    MainEmployeeList.Items.Add(AddEmployeeList.Items[i]);
                    AddEmployeeList.Items.RemoveAt(i);
                    i--;
                }
            }
        }
        MainEmployeeList.Rows = MainEmployeeList.Items.Count;

        //ModalDialog.Commit("");
        //ModalDialog.Hide();
    }

hi

Has anyone found a solution to this? I am experience the same problem.