Loading Panel not working when using filter buttons to filter and rebind radgrid

Hi,

I have radgrid where the loading panel works when I enter larger page size like from 50 to 350 items per page. Then the spinning loading panel appears. I have a group of radcombobox to make selection to filter down the amount of records. When I click on the radbutton to apply the filter selection and rebind the datatable to the radgrid datasource, the loading panel does not appear. Any help is greatly appreciated.







<telerik:RadAjaxPanel runat="server" ID="pnlRadAjax">

        <asp:Panel runat="server" ID="pnlFilter">
             <div class="contentGroupHeading">
                <table>
                    <tr>
                        <td style="width: 100%"><asp:Label ID="lblFilter" runat="server" style="text-align:center" Text="Petitions Workload Filters" /></td>
                    </tr>
                </table>
             </div>
            <br />
            <table>
                <tr>
                    <td><asp:Label runat="server" ID="lblSDNType" Text="SDN Type: " Font-Bold="true"></asp:Label></td>
                    <td><telerik:RadComboBox runat="server" ID="rcbSDNType" DataTextField="SDN_TYPE" CheckBoxes="true" EnableCheckAllItemsCheckBox="true"></telerik:RadComboBox></td>
                    <td></td>
                    <td><asp:Label runat="server" ID="lblDetermination" Text="Determination: " Font-Bold="true"></asp:Label></td>
                    <td><telerik:RadComboBox runat="server" ID="rcbDetermination" DataTextField="DETERMINATION" CheckBoxes="true" EnableCheckAllItemsCheckBox="true"></telerik:RadComboBox></td>
                    <td></td>
                    <td><asp:Label runat="server" ID="lblStatusCode" Text="Status Code: " Font-Bold="true"></asp:Label></td>
                    <td><telerik:RadComboBox runat="server" ID="rcbStatusCode" DataTextField="STATUS_CODE" CheckBoxes="true" EnableCheckAllItemsCheckBox="true"></telerik:RadComboBox></td>
                </tr>
                <tr>
                    <td><asp:Label runat="server" ID="lblCaseType" Text="Case Type: " Font-Bold="true"></asp:Label></td>
                    <td><telerik:RadComboBox runat="server" ID="rcbCaseType" DataTextField="CASE_TYPE" CheckBoxes="true" EnableCheckAllItemsCheckBox="true"></telerik:RadComboBox></td>
                    <td></td>
                    <td><asp:Label runat="server" ID="lblOwnerType" Text="Owner Type: " Font-Bold="true"></asp:Label></td>
                    <td><telerik:RadComboBox runat="server" ID="rcbOwnerType" DataTextField="OWNER_TYPE" CheckBoxes="true" EnableCheckAllItemsCheckBox="true"></telerik:RadComboBox></td>
                    <td></td>
                    <td><asp:Label runat="server" ID="lblIsPrimaryInvestigator" Text="Is Primary Investigator: " Font-Bold="true"></asp:Label></td>
                    <td><telerik:RadComboBox runat="server" ID="rcbIsPrimaryInvestigator" DataTextField="IS_PRIMARY_INVESTIGATOR" CheckBoxes="true" EnableCheckAllItemsCheckBox="true"></telerik:RadComboBox></td>
                </tr>
                <tr>
                    <td><asp:Label runat="server" ID="lblProgram" Text="Program: " Font-Bold="true"></asp:Label></td>
                    <td><telerik:RadComboBox runat="server" ID="rcbProgram" DataTextField="PROGRAM" CheckBoxes="true" EnableCheckAllItemsCheckBox="true"></telerik:RadComboBox></td>
                    <td></td>
                    <td><asp:Label runat="server" ID="lblInvestigatorDivision" Text="Investigator Division: " Font-Bold="true"></asp:Label></td>
                    <td><telerik:RadComboBox runat="server" ID="rcbInvestigatorDivision" DataTextField="INVESTIGATOR_DIVISION" CheckBoxes="true" EnableCheckAllItemsCheckBox="true"></telerik:RadComboBox></td>
                    <td colspan="4"></td>
                </tr>
                <tr>
                    <td colspan="4">&nbsp;</td>
                </tr>
                <tr>                   
                    <td><telerik:RadButton runat="server" ID="rbtnFilter" Text="Filter Results" OnClick="rbtnFilter_Click"></telerik:RadButton></td>
                    <td><telerik:RadButton runat="server" ID="rbtnClearFilter" Text="Clear Filters" OnClick="rbtnClearFilter_Click"></telerik:RadButton></td>
                </tr>
            </table>
            <br />
            <br />
        </asp:Panel>

        <br />

        <asp:Panel runat="server" ID="pnlInvestigatorPetition" >
            <div class="contentGroupHeading">
                <table>
                    <tr>
                        <td style="width: 100%"><asp:Label ID="Label1" runat="server" style="text-align:center" Text="Investigator Petition" /></td>
                        <td><asp:ImageButton ID="imgExcel" runat="server" ImageUrl="~/Images/Excel_Icon.gif" OnClick="imgExcel_Click" AlternateText="Raw Export" ToolTip="Export Unformatted Excel (for data analysis)" /></td>
                        <td>&nbsp&nbsp</td>
                        <td><asp:ImageButton runat="server" ID="imgExcelFormatted" ImageUrl="~/images/Excel_Icon.gif" OnClick="imgExcel_Click" AlternateText="Formatted Export" ToolTip="Export Formatted Excel (for presentation)" /></td>
                    </tr>
                </table>
            </div>
            <br />
            <telerik:RadGrid ID="gridInvestigatorPetition" runat="server" HeaderStyle-Font-Bold="true"
                GridLines="none"
                Skin="OFACStyle"
                AllowSorting="True"  AllowPaging="true" PageSize="50"
                EnableEmbeddedSkins="false"
                ShowGroupPanel="True"
                AutoGenerateColumns="False" 
                PagerStyle-AlwaysVisible="true"
                MasterTableView-ShowGroupFooter="true"
                OnPreRender="gridInvestigatorPetition_PreRender"
                OnItemDataBound="gridInvestigatorPetition_ItemDataBound"
                OnNeedDataSource="gridInvestigatorPetition_NeedDataSource">   
            <GroupHeaderItemStyle ForeColor="Black" Font-Size="Medium"/>
            <PagerStyle Mode="NextPrevNumericAndAdvanced"></PagerStyle>
            <MasterTableView Width="100%" AllowMultiColumnSorting="true" DataKeyNames="SDN_UID">
            <GroupByExpressions>
                <telerik:GridGroupByExpression>
                    <SelectFields>
                        <telerik:GridGroupByField FieldName="INVESTIGATOR_DIVISION" HeaderText="Investigator Division" />
                    </SelectFields>
                    <GroupByFields>
                        <telerik:GridGroupByField FieldName="INVESTIGATOR_DIVISION" HeaderText="Investigator Division" SortOrder="Ascending"  />
                    </GroupByFields>
                </telerik:GridGroupByExpression>
                <telerik:GridGroupByExpression>
                    <SelectFields>
                        <telerik:GridGroupByField FieldName="PRIMARY_INVESTIGATOR" HeaderText="Primary Investigator" />
                    </SelectFields>
                    <GroupByFields>
                        <telerik:GridGroupByField FieldName="PRIMARY_INVESTIGATOR" HeaderText="Primary Investigator" />
                    </GroupByFields>
                </telerik:GridGroupByExpression>
            </GroupByExpressions>
            <Columns>

                <telerik:GridBoundColumn SortExpression="INVESTIGATOR_DIVISION" HeaderText="Investigator Division" HeaderButtonType="TextButton" DataField="INVESTIGATOR_DIVISION" ></telerik:GridBoundColumn>
                <telerik:GridBoundColumn SortExpression="PRIMARY_INVESTIGATOR" HeaderText="Primary Investigator" HeaderButtonType="TextButton" DataField="PRIMARY_INVESTIGATOR" Aggregate="Min" FooterAggregateFormatString="{0} Total"></telerik:GridBoundColumn>
                <telerik:GridBoundColumn SortExpression="CASE_STATUS" HeaderText="Case Status" HeaderButtonType="TextButton" DataField="CASE_STATUS"></telerik:GridBoundColumn>
                <telerik:GridBoundColumn SortExpression="PRIORITY" HeaderText="Priority" HeaderButtonType="TextButton" DataField="PRIORITY"></telerik:GridBoundColumn>
                <telerik:GridBoundColumn SortExpression="CASE_ID" HeaderText="Case ID" HeaderButtonType="TextButton" DataField="CASE_ID"></telerik:GridBoundColumn>
                <telerik:GridBoundColumn SortExpression="PROGRAM" HeaderText="Program" HeaderButtonType="TextButton" DataField="PROGRAM"></telerik:GridBoundColumn>
                <telerik:GridBoundColumn SortExpression="SDN" HeaderText="SDN" HeaderButtonType="TextButton" DataField="SDN"></telerik:GridBoundColumn>
                <telerik:GridBoundColumn SortExpression="RESPONSIBLE_PARTY" HeaderText="Responsible Party" HeaderButtonType="TextButton" DataField="RESPONSIBLE_PARTY"></telerik:GridBoundColumn>
               
                <telerik:GridTemplateColumn DataField="DAYS_ON_CLOCK" UniqueName="ChartColumn" HeaderText="">
                        <ItemTemplate>
                            <div style="width: 100px; height: 50px;">
                                <telerik:RadHtmlChart ID="htmlChartDaysOnClock" runat="server" Width="100" Height="50" Legend-Appearance-Visible="false" PlotArea-YAxis-MaxValue="1000" PlotArea-XAxis-MaxValue="1000" PlotArea-XAxis-MajorGridLines-Visible="false" PlotArea-XAxis-MinorGridLines-Visible="false" PlotArea-YAxis-MajorGridLines-Visible="false" PlotArea-YAxis-MinorGridLines-Visible="false" PlotArea-YAxis-Visible="false" PlotArea-XAxis-Visible="false" >
                                    <Legend>
                                        <Appearance Visible="false">
                                        </Appearance>
                                    </Legend>
                                    <PlotArea>
                                        <Series>
                                            <telerik:BarSeries DataFieldY="quantity">
                                                <LabelsAppearance Visible="false">
                                                </LabelsAppearance>
                                                <TooltipsAppearance Color="White" />
                                            </telerik:BarSeries>
                                        </Series>
                                        <XAxis DataLabelsField="pName">
                                        </XAxis>
                                    </PlotArea>
                                </telerik:RadHtmlChart>
                            </div>
                        </ItemTemplate>
                </telerik:GridTemplateColumn>
               
               
                <telerik:GridBoundColumn SortExpression="DAYS_ON_CLOCK" HeaderText="Days On Clock" HeaderButtonType="TextButton" DataField="DAYS_ON_CLOCK"></telerik:GridBoundColumn>
                <telerik:GridBoundColumn SortExpression="NO_OF_CASES" HeaderText="# of Cases" HeaderButtonType="TextButton" DataField="NO_OF_CASES" UniqueName="TotalCases" Aggregate="Sum" FooterText="Total Cases: "></telerik:GridBoundColumn>
                <telerik:GridBoundColumn SortExpression="NO_OF_TARGETS" HeaderText="# of Targets" HeaderButtonType="TextButton" DataField="NO_OF_TARGETS" UniqueName="TotalTargets" Aggregate="Sum" FooterText="Total Targets: "></telerik:GridBoundColumn>
            </Columns>
        </MasterTableView>
            <ClientSettings ReorderColumnsOnClient="True" AllowDragToGroup="True" AllowColumnsReorder="True">
                <Selecting AllowRowSelect="True"></Selecting>
                <Resizing AllowRowResize="True" AllowColumnResize="True" EnableRealTimeResize="True" ResizeGridOnColumnResize="False"></Resizing>
            </ClientSettings>
            <GroupingSettings ShowUnGroupButton="true" RetainGroupFootersVisibility="true"></GroupingSettings>
        </telerik:RadGrid>
    </asp:Panel>

    </telerik:RadAjaxPanel>

    <telerik:RadAjaxLoadingPanel ID="LoadingPanel1" runat="server" Skin="Windows7"></telerik:RadAjaxLoadingPanel>

    </div>
</asp:Content>