lo_import() problem

Hi,

I have a problem with built-in lo_import() function.
I want to store some images in my database, so I'm doing this:

create table image(name varchar, id oid);

Next, I want to import an image '1.jpg', which resides in '/home/username/postgres/images':

INSERT INTO image (name,id) VALUES('foo',lo_import('/home/username/postgres/images/1.jpg'));

I'm receiving something like this:
ERROR: be_lo_import - 'can't open unix file'

Why? I have full rights to database and graphics files in
'/home/username/postgres/images/'.
So, what's going on?
Please help...

regards,
robert