FATAL: password authentication failed for user "postgres"

Hi,

I am using trust authentication since some years, but I need now to
authenticate the user for a specific application when connect to
postgresql database. I found "trust" ignores the password, so I changed
it in pg_hba.conf to "password".

My application is working now, but I have problems running the usual
maintenance scripts. For instance, when I am running pg_dump with
postgres user, it requires the password. The problem is it doesn't
accept the password I used in pgAdmin to connect to the same database
for the same database user.

What is wrong ?

My pg_hba.conf looks like:
local all all password
host all all 127.0.0.1/32 password

The command I am running is:
pg_dump <my_db_name> -F c -v -X disable-triggers -U postgres -h
127.0.0.1 -p 5432 -f ./test.backup

TIA,
Sabin