SQL & PL/SQL

Hi,
I work in 9.2.0.3
I have the follwing construction.
drop table t$tel_est;
drop table t$est_schraubfehler;
drop table t$est_nietfehler;
drop TYPE Niettype;
Drop Type SchraubType;
drop Type NietListe;
drop TYPE SchraubListe;
CREATE table t$est_schraubfehler (
SCHRAUB_Id NUMBER(9),
FEHLERNR VARCHAR2(10),
FEHLERTEXT VARCHAR2(200)
);

CREATE table t$est_nietfehler (
NIET_Id NUMBER(9),
FEHLERNR VARCHAR2(10),
FEHLERTEXT VARCHAR2(200)
);

CREATE OR REPLACE TYPE NietType AS OBJECT (
NERGEBNIS NUMBER(1),
POSITION NUMBER(3),
POSITIONTEXT VARCHAR2(50),
NIET_Id NUMBER(9)
);
/
Create OR REPLACE TYPE NietListe As TABLE OF NietType;
/
CREATE OR REPLACE TYPE SchraubType AS OBJECT (
SERGEBNIS NUMBER(1),
POSITION NUMBER(3),
POSITIONTEXT VARCHAR2(50),
DRM NUMBER(5,3),
WINKEL NUMBER(4),
SCHRAUB_Id NUMBER(9)
);
/
Create TYPE SchraubListe As TABLE OF SchraubType;
/
create table T$TEL_EST
(
DATETIME DATE,
MODULID NUMBER(9),
PLATZ NUMBER(5),
SYSTEM VARCHAR2(8),
VERSION NUMBER(4),
WORKID NUMBER(4),
SCHRAUB SchraubListe,
NIET NietListe
)
Nested table schraub store as Mount_schraub,
Nested table niet store as Mount_niet;

First I want to Insert just
DATETIME,MODULID,PLATZ,SYSTEM,VERSION,WORKID in T$mount.
Later I want to insert in schraub, and niet,

but I get ORA-22902. What I have to provide that it works??
Nicole