[gnome-db] Invalid GdaDataModelIter

[Andrea Zagli <azagli libero it>]

what can cause an invalid GdaDataModelIter?

i have some tables, where a simple "SELECT * FROM <tablename>" returns  
an invalid iter after gda_data_model_iter_move_next; on other tables  
of the same db it works

i'm using libgda 4.2.10 from git HEAD, with postgresql 8.3.14, under  
windows (under gnu/linux with postgresql 9.1 it works)

2 examples

CREATE TABLE atti
(
  id integer NOT NULL,
  numero character varying(10) DEFAULT ''::character varying,
  data date,
  anno integer DEFAULT 0,
  protocollo character varying(50) DEFAULT ''::character varying,
  data_protocollo date,
  gen_intervento character varying(255) DEFAULT ''::character varying,
  note character varying(255) DEFAULT ''::character varying,
  abitabilita integer DEFAULT 0,
  n_piani integer DEFAULT 0,
  n_appartamenti integer DEFAULT 0,
  pi_sottosuolo real DEFAULT 0,
  vani_utili real DEFAULT 0,
  accessori real DEFAULT 0,
  altri_vani real DEFAULT 0,
  tot_vani real DEFAULT 0,
  volumetria real DEFAULT 0,
  rec_collegato integer DEFAULT 0,
  visibile boolean DEFAULT false,
  id_tipi_atto integer DEFAULT 0,
  id_efficacia integer DEFAULT 0,
  pr_cod_prat_civilia integer DEFAULT 0,
  id_edifici integer DEFAULT 0,
  CONSTRAINT atti_pkey PRIMARY KEY (id )
)

CREATE TABLE atti_vie
(
  id_atti integer NOT NULL,
  id_vie integer NOT NULL,
  civico character varying(50) NOT NULL DEFAULT ''::character varying,
  CONSTRAINT atti_vie_pkey PRIMARY KEY (id_atti , id_vie , civico )
)

CREATE TABLE visure
(
  id integer NOT NULL,
  data timestamp without time zone,
  id_modalita_richiesta integer DEFAULT 0,
  id_richiedenti integer DEFAULT 0,
  id_qualita_di integer DEFAULT 0,
  protocollo character varying(20) DEFAULT ''::character varying,
  note text DEFAULT ''::text,
  data_conferma_richiesta timestamp without time zone,
  note_conferma_richiesta text DEFAULT ''::text,
  tipo_conferma_richiesta integer DEFAULT 0, -- 1 - confermata...
  status character varying(1) DEFAULT ''::character varying,
  CONSTRAINT visure_pkey PRIMARY KEY (id )
)

CREATE TABLE visura_atti
(
  id integer NOT NULL,
  id_visure integer,
  id_atti integer,
  numero character varying(10) DEFAULT ''::character varying,
  id_tipi_atto integer,
  data date,
  protocollo character varying(50) DEFAULT ''::character varying,
  data_protocollo date,
  intestatari character varying(255) DEFAULT ''::character varying,
  indirizzi character varying(255) DEFAULT ''::character varying,
  note text DEFAULT ''::text,
  status character varying(1) DEFAULT ''::character varying,
  tipo_conferma_richiesta integer DEFAULT 0, -- 1 - confermata...
  data_conferma_richiesta timestamp without time zone,
  note_conferma_richiesta text,
  tipo_esito_ricerca integer DEFAULT 0, -- 1 - pronto...
  data_esito_ricerca timestamp without time zone,
  note_esito_ricerca text DEFAULT ''::text,
  data_da_consegnare timestamp without time zone,
  note_da_consegnare text DEFAULT ''::text,
  data_consegna timestamp without time zone,
  note_consegna text DEFAULT ''::text,
  data_ritiro timestamp without time zone,
  note_ritiro text DEFAULT ''::text,
  data_da_ritirare timestamp without time zone,
  note_da_ritirare text DEFAULT ''::text,
  data_invio_email timestamp without time zone,
  CONSTRAINT visura_atti_pkey PRIMARY KEY (id )
)

with "atti" it returns invalid, but with "atti_vie" it works

with "visure" it works, but with "visura_atti" it returns invalid

thanks in advance