changing sequence in serial field

Hello

I noticed, that some serial field is using wrong sequence, so I altered
the default value pointing to the sequence I want, but now I cant delete
currently no longer used sequence. Did I do someting wrong changing it?

PgSQL 8.1 on Gentoo Linux.

What I try to do
DROP SEQUENCE b_prekes_br_kodas_pbk_id_seq1;

Result
ERROR: cannot drop sequence b_prekes_br_kodas_pbk_id_seq1 because table
b_prekes_br_kodas column pbk_id requires it
HINT: You may drop table b_prekes_br_kodas column pbk_id instead.

********** Error **********

ERROR: cannot drop sequence b_prekes_br_kodas_pbk_id_seq1 because table
b_prekes_br_kodas column pbk_id requires it
SQL state: 2BP01
Hint: You may drop table b_prekes_br_kodas column pbk_id instead.

--
Julius Tuskenis
Programavimo skyriaus vadovas
UAB nSoft
mob. +37068233050