Relation "autonummeringl2" does not exist

Hello,
as I have told, I am making a servlet that generates a menu and one that
changes it(deleting, adding & updating items). However it returns an error:
Relation "autonummeringl2" does not exist
autonummeringL2 is the name of a sequence that raises a field by 1 each time
it is called. Any suggestions are welcome.

Nico.

Here is the table creation sql:
 CREATE TABLE "tblMenuL2" (
    "MenuL2ID" integer DEFAULT nextval('autonummeringL2'::text) NOT NULL,
    "MenuL1ID" integer NOT NULL,
    "MenuL2Name" character varying(50) NOT NULL,
    "MenuL2Page" character varying(50),
    "MenuL2Order" smallint NOT NULL
);
ALTER TABLE ONLY "tblMenuL2"
    ADD CONSTRAINT "pkMenuL2ID" PRIMARY KEY ("MenuL2ID");
ALTER TABLE ONLY "tblMenuL2"
    ADD CONSTRAINT "fkMenuL1ID" FOREIGN KEY ("MenuL1ID") REFERENCES
"tblMenuL1"("MenuL1ID") ON UPDATE CASCADE ON DELETE CASCADE;
ALTER TABLE ONLY "tblMenuL2"
    ADD CONSTRAINT "MenuL2Volgorde" UNIQUE ("MenuL2ID", "MenuL1ID");

Here is the update query & insert. It happens during the insert query.:
UPDATE "tblMenuL2" SET "MenuL2Order"="MenuL2Order"+1 WHERE "MenuL2Order">=5;
INSERT INTO "tblMenuL2"("MenuL1ID", "MenuL2Name", "MenuL2Page",
"MenuL2Order") VALUES(1, 'naam', 'pagina', 5);