CopyObject Error 635

Hi,

I have a function like this :

CREATE FUNCTION calculPeriodesPourAccords()
RETURNS INT2
AS 'DECLARE
    lrec             RECORD;
    lrec2             RECORD;
    lint_id_regie        INT4;
    lint_num_campagne    INT4;
    lint_num_periode    INT4;
    ldt_date_trt        TIMESTAMP;

BEGIN

        ldt_date_trt := now();

        -- On désactive toues les accords
        UPDATE accord_editeur
        SET affichage_possible = 0;

        FOR lrec IN SELECT id_regie,
                num_campagne,
                num_periode
            FROM periode
            WHERE date_debut_periode <= ldt_date_trt
                AND date_fin_periode > ldt_date_trt
                AND nb_affichage < (max_affichage * 0.9)
                AND nb_clic < (max_clic * 0.9)
        LOOP
            lint_id_regie = lrec.id_regie;
            lint_num_campagne = lrec.num_campagne;
            lint_num_periode = lrec.num_periode;

            FOR lrec2 IN SELECT num_publicite
                FROM publicite
                WHERE date_debut_publicite <= ldt_date_trt
                    AND date_fin_publicite > ldt_date_trt
                    AND id_regie = lrec.id_regie
                    AND num_campagne = lrec.num_campagne
            LOOP

                UPDATE accord_editeur
                SET affichage_possible = init_affichage_possible,
                    num_periode = lint_num_periode
                WHERE id_regie = lint_id_regie
                    AND num_campagne = lint_num_campagne
                    AND num_publicite = lrec2.num_publicite;

            END LOOP;

        END LOOP;

        VACUUM accord_editeur;

        RETURN 1;
END;'
LANGUAGE 'plpgsql';


And, when I run it I've got the following error message :

ERROR:  copyObject: don't know how to copy 635

What does it mean ?

Thanx,

Guillaume.