Problem in joined table

Question

I test to join two postgis layers, one geometryc and other without geometryc data. Data are loaded properly in qgis (1.8 in Osgeo4w distribution) and the joins seem been done properly but when i try to select data from Attribute table in layer "expanded" with the join, integer fields have a beavieur like text fiels and query results are not correct (1.9 version data are missing when do the join).

My table structure are:

 CREATE TABLE "Municipi_Dades"
 (
  "MUNICIPI" character varying(80) NOT NULL,
  "POBLACIO" bigint,
  CONSTRAINT "Primary" PRIMARY KEY ("MUNICIPI" )
 )

and

 CREATE TABLE "Municipi_Area"
 (
  gid integer NOT NULL,
  "MUNICIPI" character varying(80),
  "COMARCA" character varying(80),
  "PROVINCIA" character varying(80),
  "NOM_MUNI" character varying(80),
  "NOMN_MUNI" character varying(80),
  "NOMG_MUNI" character varying(80),
  "CAP_MUNI" character varying(80),
  "CAPN_MUNI" character varying(80),
  "CAPG_MUNI" character varying(80),
  "SUP_MUNI" double precision,
  "ORSUP_MUNI" character varying(80),
  the_geom geometry,
  CONSTRAINT "Municipi_Area_pkey" PRIMARY KEY (gid ),
  CONSTRAINT enforce_dims_the_geom CHECK (ndims(the_geom) = 2),
  CONSTRAINT enforce_srid_the_geom CHECK (srid(the_geom) = (-1))
 )

I joint the two tables using field "MUNICIPI" and get problem with the field "POBLACIO" (it show as integer in schema table but query as beaviour like text)

I tested gvSIG 1.12 portable for this two tables and join work properly.

Is this a bug in Attribute table query?