White space appears above grid when using AJAX manager

[drpcken]

This problem has been driving me crazy.  I have a RadGrid with an Ajax Manager wired up to it.  See screenshot:
http://i5.photobucket.com/albums/y176/drpcken/1-2.png

Everything looks great until I sort by a column, then for no reason at all a whitespace (about 8 pixels) appears above the grid.  See screenshot:
http://i5.photobucket.com/albums/y176/drpcken/2.png

It seems that anytime I click on a control that is wired up to the AJAX manager this happens.  I have a button ABOVE the grid (it's not even a part of the grid) and its wired up to the Ajax Manager, when I click it I get the same behavior: a white space above the grid.  When I remove the AJAX manager it works, but of course the whole page posts back with no AJAX.  I've tried everything I can think of to fix this:  I've removed ALL CSS from the page, but I get the same problem.  I've removed the wrapper around the grid, same problem.  I've removed the loading panel, same problem.  I've removed every single server-side method and client side javascript but get the same problem.  The code for the grid:

<div class="CensusGrid">
        <asp:Button ID="btnRefreshCustomers" runat="server" Style="display: none;"  />
        <telerik:RadGrid ID="RadGrid1" runat="server" AutoGenerateColumns="False" DataSourceID="LinqDataSource1"
            GridLines="None" Skin="WebBlue" AllowMultiRowSelection="True" AllowSorting="True"
            OnItemDataBound="RadGrid1_ItemDataBound">
            <MasterTableView AutoGenerateColumns="false" DataKeyNames="CensusID" DataSourceID="LinqDataSource1">
                <RowIndicatorColumn>
                    <HeaderStyle Width="20px"></HeaderStyle>
                </RowIndicatorColumn>
                <ExpandCollapseColumn>
                    <HeaderStyle Width="20px"></HeaderStyle>
                </ExpandCollapseColumn>
                <Columns>
                    <telerik:GridClientSelectColumn UniqueName="ClientSelectColumn">
                        <ItemStyle Width="27px" Wrap="false" />
                        <HeaderStyle Width="27px" Wrap="false" />
                    </telerik:GridClientSelectColumn>
                    <telerik:GridTemplateColumn DataField="LastName" HeaderText="Name"
                        SortExpression="LastName" UniqueName="LastName">
                        <ItemTemplate>
                            <asp:Label ID="LastNameLabel" runat="server" Text='<%# Eval("LastName") %>'></asp:Label>,&nbsp;
                            <asp:Label ID="FirstNameLabel" runat="server" Text='<%# Eval("FirstName") %>'></asp:Label>&nbsp;
                            <asp:ImageButton ID="hasAccess" ImageUrl='<%# Eval("AllowClientAccess", "images/lock_{0}.png") %>'
                                runat="server" />
                        </ItemTemplate>
                    </telerik:GridTemplateColumn>
                    <telerik:GridBoundColumn DataField="DOB" DataType="System.DateTime" HeaderText="DOB"
                        SortExpression="DOB" UniqueName="DOB" DataFormatString="{0:d}">
                    </telerik:GridBoundColumn>
                    <telerik:GridBoundColumn DataField="MaritalStatus" HeaderText="MaritalStatus" SortExpression="MaritalStatus"
                        UniqueName="MaritalStatus">
                    </telerik:GridBoundColumn>
                    <telerik:GridBoundColumn DataField="AddressCity" HeaderText="AddressCity" SortExpression="AddressCity"
                        UniqueName="AddressCity">
                    </telerik:GridBoundColumn>
                    <telerik:GridBoundColumn DataField="AddressState" HeaderText="AddressState" SortExpression="AddressState"
                        UniqueName="AddressState">
                    </telerik:GridBoundColumn>
                    <telerik:GridBoundColumn DataField="EmailAddress" HeaderText="EmailAddress" SortExpression="EmailAddress"
                        UniqueName="EmailAddress">
                    </telerik:GridBoundColumn>
                    <telerik:GridBoundColumn DataField="DateOfHire" DataType="System.DateTime" HeaderText="DateOfHire"
                        SortExpression="DateOfHire" UniqueName="DateOfHire" DataFormatString="{0:d}">
                    </telerik:GridBoundColumn>
                    <telerik:GridBoundColumn DataField="JobDescription" HeaderText="JobDescription" SortExpression="JobDescription"
                        UniqueName="JobDescription">
                    </telerik:GridBoundColumn>
                    <telerik:GridBoundColumn DataField="flag" UniqueName="flag" Visible="false">
                    </telerik:GridBoundColumn>
                    <telerik:GridTemplateColumn>
                        <ItemStyle Width="29px" Wrap="false" />
                        <HeaderStyle Width="29px" />
                        <ItemTemplate>
                            <a id="HyperLink1" runat="server" class="thickbox" title='<%# "Dependents for <b>" + Eval("FirstName") + " " + Eval("LastName") + "</b>" %>'
                                href='<%# Eval("censusID", "Dependents.aspx?c={0}&TB_iframe=true&height=550&width=600") %>'>
                                <asp:Image ID="Image2" runat="server" ImageUrl="images/she_users.png" ToolTip="Add/Edit Dependents" />
                            </a>
                        </ItemTemplate>
                    </telerik:GridTemplateColumn>
                    <telerik:GridTemplateColumn>
                        <ItemStyle Width="29px" Wrap="false" />
                        <HeaderStyle Width="29px" />
                        <ItemTemplate>
                            <a id="editUser" runat="server" class="thickbox" title='<%# "Details for <b>" + Eval("FirstName") + " " + Eval("LastName") + "</b>" %>'
                                href='<%# Eval("censusID", "CensusDetails.aspx?c={0}&TB_iframe=true&height=550&width=600") %>'>
                                <asp:Image ID="Image1" runat="server" ImageUrl="images/Edit.gif" ToolTip="Edit Employee" />
                            </a>
                        </ItemTemplate>
                    </telerik:GridTemplateColumn>
                    <telerik:GridTemplateColumn>
                        <ItemStyle Width="29px" Wrap="false" />
                        <HeaderStyle Width="29px" />
                        <ItemTemplate>

                        </ItemTemplate>
                    </telerik:GridTemplateColumn>
                </Columns>
            </MasterTableView>
            <ClientSettings>
                <Selecting AllowRowSelect="True" EnableDragToSelectRows="False" />
                <Scrolling AllowScroll="True" ScrollHeight="489px" UseStaticHeaders="True" />
            </ClientSettings>
        </telerik:RadGrid>
    </div>
    <asp:LinqDataSource ID="LinqDataSource1" runat="server" ContextTypeName="clientBenefitDataContext"
            OrderBy="LastName" TableName="Census" Where="ContactID == @ContactID" OnSelecting="LinqDataSource1_Selecting">
            <WhereParameters>
                <asp:ControlParameter ControlID="hiddenContactID" DefaultValue="0" Name="ContactID"
                    PropertyName="Value" Type="Int32" />
            </WhereParameters>
        </asp:LinqDataSource>

And here is my AjaxManager which is below the grid:

<telerik:RadAjaxManager ID="RadAjaxManager1" runat="server">
        <AjaxSettings>
            <telerik:AjaxSetting AjaxControlID="lblToggle">
                <UpdatedControls>
                    <telerik:AjaxUpdatedControl ControlID="RadGrid1" />
                </UpdatedControls>
            </telerik:AjaxSetting>
            <telerik:AjaxSetting AjaxControlID="RadGrid1">
                <UpdatedControls>
                    <telerik:AjaxUpdatedControl ControlID="RadGrid1" />
                </UpdatedControls>
            </telerik:AjaxSetting>
        </AjaxSettings>
    </telerik:RadAjaxManager>

This problem has been driving me crazy.  Does anyone see anything I don't?

[drpcken]

Ok within seconds of posting this I figured it out.  It was the hidden button above the grid.  I moved it to the bottom of the grid and it works fine... Figures :)