Ocultar columnas Datagrid + paginacion

[Nombela]

Cargar el grid:

private void CargarGrid()
{
//Response.Write(ViewState["sql"].ToString());
string connectionString = ConfigurationSettings.AppSettings["conexion"];
SqlConnection conexion= new SqlConnection(connectionString);
SqlCommand comando = new SqlCommand (ViewState["sql"].ToString(),conexion);
SqlDataAdapter adaptador = new SqlDataAdapter(comando);
SqlCommandBuilder generarcomandos = new SqlCommandBuilder(adaptador);
DataSet registros = new DataSet();
adaptador.Fill(registros,"OTs");
DataGrid1.DataSource=registros.Tables["OTs"].DefaultView;
DataGrid1.HeaderStyle.CssClass="header";
DataGrid1.AlternatingItemStyle.CssClass="par";

//Response.Write(registros.Tables["OTs"].Columns.Count.ToString());
//registros.Tables["OTs"].Columns["Ot"].ColumnMapping = MappingType.Hidden;
DataGrid1.DataBind();
if (DataGrid1.Items.Count < 1)
{
DataGrid1.Visible=false;
aviso.Visible=true;
aviso.Text="No hay ningun resultado disponible";
aviso.Style["color"] = "609742";
aviso.Style["font-weight"] = "normal";
}
else
aviso.Visible=false;
}

para la recarga en la paginacion:

DataGrid1.CurrentPageIndex = 0;
DataGrid1.CurrentPageIndex = e.NewPageIndex;
CargarGrid();

ocultar la fila repetida:

private void ocultar(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
e.Item.Cells.RemoveAt(1);
}