NOT NULL wird ignoriert

Hallo,

ich verwende postgreSQL 7.4.8 und habe folgende Tabelle erstellt:

CREATE TABLE pcmask
(
customer char(3) NOT NULL,
system char(3) NOT NULL,
transmitter char(3) NOT NULL,
equipment char(3) NOT NULL,
layout char(3) NOT NULL,
performance char(3) NOT NULL,
radio char(3) NOT NULL,
output char(3) NOT NULL,
voltage char(3) NOT NULL,
charger char(3) NOT NULL,
destination char(3) NOT NULL,
xtra char(3) NOT NULL,
cus_text char(40) NOT NULL,
sys_text char(40) NOT NULL,
tv_text char(40) NOT NULL,
e_text char(40) NOT NULL,
l_text char(40) NOT NULL,
pp_text char(40) NOT NULL,
r_text char(40) NOT NULL,
o_text char(40) NOT NULL,
v_text char(40) NOT NULL,
c_text char(40) NOT NULL,
dd_text char(40) NOT NULL,
x_text char(40) NOT NULL,
cus_text_en char(40),
sys_text_en char(40),
tv_text_en char(40),
e_text_en char(40),
l_text_en char(40),
pp_text_en char(40),
r_text_en char(40),
o_text_en char(40),
v_text_en char(40),
c_text_en char(40),
dd_text_en char(40),
x_text_en char(40),
pcid int4 NOT NULL
)

Mit Index
CREATE UNIQUE INDEX idx_codetext
ON pcmask
USING btree
(cus_text, sys_text, tv_text, e_text, l_text, pp_text, r_text, o_text, v_text, c_text, dd_text, x_text);

Nun lautet z.B. mein INSERT Statement folgendermaßen:
INSERT INTO pcmask(pcid,customer,system,transmitter,equipment,layout,performance,radio,output,voltage,charger,destination,xtra,cus_text,sys_text,tv_text,e_text,l_text,pp_text,r_text,o_text,v_text,c_text,dd_text,x_text) VALUES((SELECT pcid FROM pc WHERE produktcode='abcd'),
'005', '716', 'M5', '6', '1', '11', '1', '2', '4', '1', 'US', '0', '', '', '', '', '', '', '', '', '', '', '', '');

Er sollte nun eigentlich meckern, dass er keine Null Werte ('') schreiben darf, aber das tut er nicht. Woran kann dies liegen?!

Danke schonmal im Voraus

Daniel Seichter