FastCgi / PostgreSQL: FATAL: Ident authentication failed for user "user_name"

Hi,

I have a strange problem running Django on a GrokThis.net shared
hosting account:

Environment:
------------------------------------------------------
Apache/2.0.59 (Unix)
mod_fastcgi/2.4.2
PostgreSQL 8.1.3
------------------------------------------------------

settings.py:
------------------------------------------------------
DATABASE_ENGINE = 'postgresql'
DATABASE_USER = 'user_name'
DATABASE_PASSWORD = '***'
------------------------------------------------------
or
------------------------------------------------------
DATABASE_ENGINE = 'postgresql_psycopg2'
DATABASE_USER = 'user_name'
DATABASE_PASSWORD = '***'
------------------------------------------------------

Django on FastCgi renders this error:
------------------------------------------------------
Traceback (most recent call last):
File "/home/shared/user_name/django_src/django/template/__init__.py" in
render_node
706. result = node.render(context)
File "/home/shared/user_name/django_src/django/template/__init__.py" in
render
757. return self.encode_output(output) File
"/home/shared/user_name/django_src/django/template/__init__.py" in
encode_output
739. return str(output)
File "/home/shared/user_name/django_src/django/db/models/query.py" in
__repr__
97. return repr(self._get_data())
File "/home/shared/user_name/django_src/django/db/models/query.py" in
_get_data
430. self._result_cache = list(self.iterator()) File
"/home/shared/user_name/django_src/django/db/models/query.py" in
iterator
170. cursor = connection.cursor()
File
"/home/shared/user_name/django_src/django/db/backends/postgresql/base.py"
in cursor
43. self.connection = Database.connect(conn_string)

OperationalError at /
FATAL: Ident authentication failed for user "user_name"
------------------------------------------------------

Surprisingly, I can succesfully connect to the db using either:

- psql - PostgreSQL interactive terminal
- django-admin.py shell
- django-admin.py dbshell
- django development server
- Navicat PostgreSQL from my own pc using ssh-tunnel

The only circumstance in which I cannot seem to connect to the db is
using the FastCgi instance, although it is configured to use the same
settings file as above...

[1] Can anybody shed a light on the difference between the FastCgi
context and the ones mentioned above? I suspect it must have something
to do with pg_hba.conf... but I can't see the difference between the
contexts.

[2] How do I resolve this issue? :)

Thanks very much in advance!

Best regards,
bin