query slower on 9.3

SELECT mo.referencia AS "REFERENCIA",
       ent.unidades AS "ENTRADA",
       ven.unidades AS "VENDIDAS",
       stock.unidades AS "STOCK DISP",
       stock.num_tiendas AS "TIENDAS STOCK",
       CASE
          WHEN ent.unidades = 0
             THEN NULL
          ELSE
             CASE
                WHEN ((ven.unidades::numeric / ent.unidades::numeric) * 100.0)::int < 100
                   THEN ((ven.unidades::numeric / ent.unidades::numeric) * 100.0)::int
                ELSE 100
             END
       END AS "%% VEN",
       (taprov.precio * (1.0 + (mo.tipo_iva / 100.0)))::numeric(7,2) AS "COSTO IVA INC.",
       ta3.precio AS "PVP RECOME.",
       ta1.precio AS "PVP ACTUAL"

FROM modelo AS mo

   JOIN (SELECT mo.modelo_id AS id_modelo,
                SUM(lin.unidades_reales)::int AS unidades,
                MIN(cab.time_stamp_recepcion)::date AS min_fecha

         FROM modelo AS mo
            JOIN articulo AS art ON art.id_modelo = mo.modelo_id
            JOIN albaran_entrada_linea As lin ON lin.id_articulo = art.articulo_id
            JOIN albaran_entrada_cabecera AS cab ON cab.albaran_id = lin.id_albaran

         WHERE cab.id_almacen_destino = 109

         GROUP BY mo.modelo_id

         HAVING MIN(cab.time_stamp_recepcion)::date = (current_date - interval '30')::date) AS ent ON ent.id_modelo = mo.modelo_id

   JOIN (SELECT mo.modelo_id AS id_modelo,
                (CASE
                   WHEN SUM(tic.unidades) > 0
                      THEN  SUM(tic.unidades)
                   ELSE 0
                END
                +
                CASE
                   WHEN SUM(res.unidades) > 0
                      THEN SUM(res.unidades)
                   ELSE 0
                END)::int AS unidades
         FROM modelo AS mo
            JOIN articulo AS art ON art.id_modelo = mo.modelo_id

            LEFT JOIN (SELECT lin.id_articulo,
                              SUM(lin.unidades) AS unidades
                       FROM ticket_cabecera AS cab
                          JOIN ticket_linea AS lin ON lin.id_ticket = cab.ticket_id
                                                   AND lin.tienda = cab.tienda
                       WHERE cab.tienda = 109
                       GROUP BY lin.id_articulo) AS tic ON tic.id_articulo = art.articulo_id

            LEFT JOIN (SELECT lin.id_articulo,
                              SUM(lin.unidades) AS unidades
                       FROM reserva_cabecera AS cab
                          JOIN reserva_linea AS lin ON lin.id_reserva = cab.reserva_id
                                                    AND lin.tienda = cab.tienda
                       WHERE cab.tienda = 109
                          AND cab.recogido = TRUE
                       GROUP BY lin.id_articulo) AS res ON res.id_articulo = art.articulo_id

       GROUP BY mo.modelo_id) AS ven ON ven.id_modelo = mo.modelo_id

   JOIN tarifa_modelo_precio AS ta3 ON ta3.id_modelo = mo.modelo_id
                                   AND ta3.id_tarifa = 3
   JOIN tarifa_proveedor_modelo_precio AS taprov ON taprov.id_modelo = mo.modelo_id
                                                AND taprov.id_tarifa = 3

   LEFT JOIN tarifa_modelo_precio AS ta1 ON ta1.id_modelo = mo.modelo_id
                                        AND ta1.id_tarifa = 1

   LEFT JOIN (SELECT mo.modelo_id AS id_modelo,
                     (SUM(st.stock) - SUM(st.reservado))::int AS unidades,
                     COUNT(DISTINCT(st.tienda)) AS num_tiendas

              FROM ubicacion_stock AS st
                 JOIN articulo AS art ON art.articulo_id = st.id_articulo
                 JOIN modelo AS mo ON mo.modelo_id = art.id_modelo

              WHERE st.tienda = 109
                AND (st.stock - st.reservado) > 0
              GROUP BY mo.modelo_id) AS stock ON stock.id_modelo = mo.modelo_id

WHERE mo.id_seccion <> 4
  AND (ent.unidades <> 0 OR ven.unidades <> 0)

ORDER BY "REFERENCIA";