Gridview using sqldatasource

Question

Im working using Gridview and Sqldatasource, so , when Im tried to use the updatecommand, but when I clicked on, nothing happen, so, if I save a new record and after click on update command button , so , it works well. do you have any idea about whats happening ? the next is my code snipped

         <asp:GridView  ID="gvInfoCobradores" runat="server" CellPadding="4" 
             ForeColor="#333333" GridLines="None" AutoGenerateEditButton="True" 
             OnRowEditing="gvInfoAdmin_RowEditing" OnRowUpdating="gvInfoAdmin_RowUpdating" 
             DataSourceID="dsCobradorInfo" DataKeyNames="ID_Cobrador" Width="50%">
        <AlternatingRowStyle BackColor="White" />
             <Columns>
                 <asp:CommandField ShowDeleteButton="True" />
             </Columns>
        <EditRowStyle BackColor="#2461BF" />
        <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
        <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
        <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
        <RowStyle BackColor="#EFF3FB" />
        <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />



    </asp:GridView>


        <asp:SqlDataSource ID="dsCobradorInfo" runat="server" ConnectionString="<%$ ConnectionStrings:SeminarioConnectionString %>" 
        SelectCommand="SELECT * FROM [UsuariosSistema].[Cobrador]" 
        OldValuesParameterFormatString="original_{0}" ConflictDetection="CompareAllValues" 
        DeleteCommand="DELETE FROM [UsuariosSistema].[Cobrador] WHERE [ID_Cobrador] = @original_ID_Cobrador AND [NombreUsuarioCobrador] = @original_NombreUsuarioCobrador AND [PasswordCobrador] = @original_PasswordCobrador AND [NombreCobrador] = @original_NombreCobrador AND [ApellidoPaternoCobrador] = @original_ApellidoPaternoCobrador AND [ApellidoMaternoCobrador] = @original_ApellidoMaternoCobrador AND (([TelCobrador] = @original_TelCobrador) OR ([TelCobrador] IS NULL AND @original_TelCobrador IS NULL)) AND (([CelCobrador] = @original_CelCobrador) OR ([CelCobrador] IS NULL AND @original_CelCobrador IS NULL)) AND (([CorreElectronicoCobrador] = @original_CorreElectronicoCobrador) OR ([CorreElectronicoCobrador] IS NULL AND @original_CorreElectronicoCobrador IS NULL))" 
        InsertCommand="INSERT INTO [UsuariosSistema].[Cobrador] ([NombreUsuarioCobrador], [PasswordCobrador], [NombreCobrador], [ApellidoPaternoCobrador], [ApellidoMaternoCobrador], [TelCobrador], [CelCobrador], [CorreElectronicoCobrador]) VALUES (@NombreUsuarioCobrador, @PasswordCobrador, @NombreCobrador, @ApellidoPaternoCobrador, @ApellidoMaternoCobrador, @TelCobrador, @CelCobrador, @CorreElectronicoCobrador)" 

             UpdateCommand="UPDATE [UsuariosSistema].[Cobrador] SET [NombreUsuarioCobrador] = @NombreUsuarioCobrador, [PasswordCobrador] = @PasswordCobrador, [NombreCobrador] = @NombreCobrador, [ApellidoPaternoCobrador] = @ApellidoPaternoCobrador, [ApellidoMaternoCobrador] = @ApellidoMaternoCobrador, [TelCobrador] = @TelCobrador, [CelCobrador] = @CelCobrador, [CorreElectronicoCobrador] = @CorreElectronicoCobrador WHERE [ID_Cobrador] = @original_ID_Cobrador AND [NombreUsuarioCobrador] = @original_NombreUsuarioCobrador AND [PasswordCobrador] = @original_PasswordCobrador AND [NombreCobrador] = @original_NombreCobrador AND [ApellidoPaternoCobrador] = @original_ApellidoPaternoCobrador AND [ApellidoMaternoCobrador] = @original_ApellidoMaternoCobrador AND (([TelCobrador] = @original_TelCobrador) OR ([TelCobrador] IS NULL AND @original_TelCobrador IS NULL)) AND (([CelCobrador] = @original_CelCobrador) OR ([CelCobrador] IS NULL AND @original_CelCobrador IS NULL)) AND (([CorreElectronicoCobrador] = @original_CorreElectronicoCobrador) OR ([CorreElectronicoCobrador] IS NULL AND @original_CorreElectronicoCobrador IS NULL))">
        <DeleteParameters>
            <asp:Parameter Name="original_ID_Cobrador" Type="Int32" />
            <asp:Parameter Name="original_NombreUsuarioCobrador" Type="String" />
            <asp:Parameter Name="original_PasswordCobrador" Type="String" />
            <asp:Parameter Name="original_NombreCobrador" Type="String" />
            <asp:Parameter Name="original_ApellidoPaternoCobrador" Type="String" />
            <asp:Parameter Name="original_ApellidoMaternoCobrador" Type="String" />
            <asp:Parameter Name="original_TelCobrador" Type="String" />
            <asp:Parameter Name="original_CelCobrador" Type="String" />
            <asp:Parameter Name="original_CorreElectronicoCobrador" Type="String" />
        </DeleteParameters>
        <InsertParameters>
            <asp:Parameter Name="NombreUsuarioCobrador" Type="String" />
            <asp:Parameter Name="PasswordCobrador" Type="String" />
            <asp:Parameter Name="NombreCobrador" Type="String" />
            <asp:Parameter Name="ApellidoPaternoCobrador" Type="String" />
            <asp:Parameter Name="ApellidoMaternoCobrador" Type="String" />
            <asp:Parameter Name="TelCobrador" Type="String" />
            <asp:Parameter Name="CelCobrador" Type="String" />
            <asp:Parameter Name="CorreElectronicoCobrador" Type="String" />
        </InsertParameters>
        <UpdateParameters>
            <asp:Parameter Name="NombreUsuarioCobrador" Type="String" />
            <asp:Parameter Name="PasswordCobrador" Type="String" />
            <asp:Parameter Name="NombreCobrador" Type="String" />
            <asp:Parameter Name="ApellidoPaternoCobrador" Type="String" />
            <asp:Parameter Name="ApellidoMaternoCobrador" Type="String" />
            <asp:Parameter Name="TelCobrador" Type="String" />
            <asp:Parameter Name="CelCobrador" Type="String" />
            <asp:Parameter Name="CorreElectronicoCobrador" Type="String" />
            <asp:Parameter Name="original_ID_Cobrador" Type="Int32" />
            <asp:Parameter Name="original_NombreUsuarioCobrador" Type="String" />
            <asp:Parameter Name="original_PasswordCobrador" Type="String" />
            <asp:Parameter Name="original_NombreCobrador" Type="String" />
            <asp:Parameter Name="original_ApellidoPaternoCobrador" Type="String" />
            <asp:Parameter Name="original_ApellidoMaternoCobrador" Type="String" />
            <asp:Parameter Name="original_TelCobrador" Type="String" />
            <asp:Parameter Name="original_CelCobrador" Type="String" />
            <asp:Parameter Name="original_CorreElectronicoCobrador" Type="String" />
        </UpdateParameters>
    </asp:SqlDataSource>

Thanks in advance!!