8.0.0beta2 and plpgsql

CORRECTION,

even if I define a stupid "hello world" trigger function the problem is present:

for example

CREATE FUNCTION sns_action () RETURNS TRIGGER AS '
BEGIN
RAISE NOTICE ''hello world!'';
RETURN NEW;
END;
' LANGUAGE 'plpgsql';

CREATE TRIGGER sns_action_tr BEFORE UPDATE OR INSERT ON "SNS_DATA" FOR EACH ROW EXECUTE PROCEDURE sns_action();

The table is:

Table "public.SNS_DATA"
Column | Type | Modifiers
----------------------+-----------------------------+--------------------
Ordine | integer | not null default 0
Cod_Par | character varying(100) | not null
Cod_Ana | character varying(100) | not null
Valore | character varying(255) |
Descriz | character varying(512) |
Un_Mis | character varying(70) |
hash | integer |
valid | boolean | default true
alarm | boolean | default false
Cod_Luogo | character varying(30) |
Data_Arrivo_Campione | timestamp without time zone |
site_id | integer |
Cod_Luogo_v | character varying(30) |
repeated_val | boolean | default false
Indexes:
"sns_data2_pkey" PRIMARY KEY, btree ("Ordine", "Cod_Ana", "Cod_Par")
"sns_datacodluogo2" btree ("Cod_Luogo")
"sns_datatimefield2" btree ("Data_Arrivo_Campione")
"sns_siteid2" btree (site_id)
"sns_valid2" btree ("valid")
"snsdata_codana" btree ("Cod_Ana")
"snsdata_codpar" btree ("Cod_Par")
Foreign-key constraints:
"$2" FOREIGN KEY ("Cod_Ana") REFERENCES "SNS_ANA"("Cod_Ana") ON DELETE CASCADE
Triggers:
sns_action_tr BEFORE INSERT OR UPDATE ON "SNS_DATA" FOR EACH ROW EXECUTE PROCEDURE sns_action()

and the insert operation is:

INSERT INTO "SNS_DATA" ("Cod_Par","Cod_Ana","Valore","Descriz","Un_Mis","Cod_Luogo","Data_Arrivo_Campione",site_id,hash) VALUES ('24359','2004-09-11 03:00:0057',19.8,'Temperatura media []','°C','57',timestamp '2004-09-11 03:00:00',1,-574156802);

Thanks in advance for the help.
RedS