common_fields: permission denied

Hi there,

I have a problem accessing my postgres database when using a specific
user...

If I run and pg_dumpall using the postgres linux user I have no problem.
Then I tried to add a new user only for one database (let say "user1" and
"db1"). My pg_hba.conf looks like :

local   all         all                                             trust
host    all         all         127.0.0.1         255.255.255.255   trust
host    all         all         0.0.0.0           255.255.255.255   reject

When I try to run "./pg_dump --username=user1 --password db1" I have an
error saying :

pg_dump: Attempt to lock table "common_fields" failed.  ERROR:
common_fields: permission denied


Any idea ?

Thanks

Oliver