Balloon Popup Extender

I have a modal popup extender that shows a grid view. The grid view includes an imagebutton that triggers a balloon popup on mouse over. THE BALLOON POPS UP ok BUT IT DOESNT DISPLAY THE DATA IN THE ASSOCIATED panel.

<asp:ImageButton ID="ImageButton2" runat="server" CommandName="log" CommandArgument='<%# Bind("rideid") %>' 
                                ImageUrl="~/Images/Icons/doc_page.png" /><ajaxToolkit:BalloonPopupExtender ID="ImageButton2_BalloonPopupExtender" runat="server" CustomCssUrl="" 
                                 Enabled="True" ExtenderControlID="" BalloonPopupControlID="Panel1" 
                                TargetControlID="ImageButton2" DisplayOnMouseOver="true" DisplayOnClick="true" />

<asp:Panel ID="Panel1" runat="server"><asp:FormView ID="FormView1" runat="server" DataKeyNames="rideid"><ItemTemplate>
                    riderid:<asp:Label ID="rideridLabel" runat="server" Text='<%# Bind("riderid") %>' /><br />
                    rideid:<asp:Label ID="rideidLabel" runat="server" Text='<%# Eval("rideid") %>' /><br />
                    Distance:<asp:Label ID="DistanceLabel" runat="server" Text='<%# Bind("Distance") %>' /><br />
                    Scale:<asp:Label ID="ScaleLabel" runat="server" Text='<%# Bind("Scale") %>' /><br />
                    century:<asp:Label ID="centuryLabel" runat="server" Text='<%# Bind("century") %>' /><br />
                    Ride Time:<asp:Label ID="Ride_TimeLabel" runat="server" Text='<%# Bind("[Ride Time]") %>' /><br />
                    Total Time:<asp:Label ID="Total_TimeLabel" runat="server" Text='<%# Bind("[Total Time]") %>' /><br />
                    ridedate:<asp:Label ID="ridedateLabel" runat="server" Text='<%# Bind("ridedate") %>' /><br />
                    AVG Spd:<asp:Label ID="AVG_SpdLabel" runat="server" Text='<%# Bind("[AVG Spd]") %>' /><br />
                    description:<asp:Label ID="descriptionLabel" runat="server" Text='<%# Bind("description") %>' /><br />
                    Temp:<asp:Label ID="TempLabel" runat="server" Text='<%# Bind("Temp") %>' /><br />
                    Elevation Gain:<asp:Label ID="Elevation_GainLabel" runat="server" Text='<%# Bind("[Elevation Gain]") %>' /><br /></ItemTemplate></asp:FormView>

 protected void GridView2_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "log")
        {
            int rideid = Convert.ToInt32(e.CommandArgument);
            stats st = new stats();
            FormView1.DataSource = st.getridedetail(rideid);
            FormView1.DataBind();
            ImageButton2_BalloonPopupExtender.Show();
        }
    }

Apparently there is no Show for the Balloon Popup?