Visual Basic - recordset lento

Dim RsSm As New ADODB.Recordset

            MskDesde.Text = "01/11/2013"

               sql = ("select sum(importe),sum(entrega) from ventas where idcli= '" & IdCli & "'and fecha between '" & MskDesde.Text & "' and '" & MskFecha.Text & "'and esventa='" & 1 & "'and blng='" & 0 & "'")

           Set RsSm = cn.Execute(sql)

           If RsSm.EOF = False Then

            impor = RsSm(0)

            entr = RsSm(1)

           If IsNull(impor) Then

            impor = "0"

           End If

           If IsNull(entr) Then

            entr = "0"

           End If

         End If

            Saldo = impor - entr

              cn.Execute ("update clientes set salold=" & Saldo & " where id_cliente='" & IdCli & "'")

   RsCli.MoveNext

   Barra.Value = Barra.Value + 1

   Loop

   End If