Gridview problem for stackoverflow

<asp:GridView ID="grdOffices" runat="server" AllowSorting="True" AutoGenerateColumns="False"
        CellPadding="4" CssClass="UI_small" DataSourceID="objOffices" EnableModelValidation="True"
        ForeColor="#333333" GridLines="None">
        <RowStyle BackColor="#F7F6F3" Font-Size="Small" ForeColor="#333333" />
        <Columns>
            <asp:BoundField DataField="COF_Name" HeaderText="Name" SortExpression="COF_Name" />
            <asp:BoundField DataField="COF_Guid" HeaderText="Id" SortExpression="COF_Guid" />
            <asp:CheckBoxField DataField="COF_MapNGuideEnabled" HeaderText="Map'N'Guide" SortExpression="COF_Guid" >

            </asp:CheckBoxField>
            <asp:BoundField DataField="COF_InvoiceReference" HeaderText="Inv. Ref" SortExpression="COF_InvoiceReference" />
            <asp:BoundField DataField="COF_AddrLine1Inv" HeaderText="Receiver" SortExpression="COF_AddrLine1Inv" />
            <asp:BoundField DataField="COF_StreetInv" HeaderText="Street" SortExpression="COF_StreetInv" />
            <asp:BoundField DataField="COF_StreetNoInv" HeaderText="Street#" SortExpression="COF_StreetNoInv">
                <controlstyle Width="32px">
                </controlstyle>
            </asp:BoundField>
            <asp:BoundField DataField="COF_ZipCodeInv" HeaderText="ZIP" SortExpression="COF_ZipCodeInv">
                <controlstyle Width="50px">
                </controlstyle>
            </asp:BoundField>
            <asp:BoundField DataField="COF_CityInv" HeaderText="City" SortExpression="COF_CityInv" />
            <asp:BoundField DataField="COF_CountryInv" HeaderText="Country" SortExpression="COF_CountryInv" />
            <asp:BoundField DataField="COF_VATNumber" HeaderText="VAT#" SortExpression="COF_VATNumber">
                <controlstyle Width="80px">
                </controlstyle>
            </asp:BoundField>

            <asp:CommandField ShowEditButton="True" EditImageUrl="~\Images\table_edit.jpg"
            CancelImageUrl="~\Images\stop.png"
            UpdateImageUrl="~\Images\accept.png"
            headertext="Edit">
                <ItemStyle Font-Size="X-Small" />
            </asp:CommandField>
        </Columns>
        <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
        <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
        <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
        <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" Font-Size="Small" />
        <EditRowStyle BackColor="#999999" />
        <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
    </asp:GridView>