Permissions to users ??? (FATAL: Ident authentication failed for user)

Hi,

Im about to make a small webapplication using Postgresql.

My system is Debian 3.1 Sarge with Postgresql 8.1 from backports.org.

What I want to do is have my superuser, which also have a system account,
to create a database called wt, and then create two users (wt_public,
wt_admin) for use in the webapplication.

The two users for the webapplication should then have to following
permissions:
wt_public: only have permission to do a select, nothing else.
wt_admin: have all permissions on the database wt incl. creating and
dropping tables etc.

I've installed Postgresql and created my own superuser, and then, using my
superuser, I created the two users (wt_public, wt_admin)

I then created a database called wt, and added the following to pg_hba.conf:
host    wt          wt_admin    127.0.0.1/32          md5
host    wt          wt_public   127.0.0.1/32          md5

Then restarted postgresql and tried to login with:
psql -U wt_admin -W wt
but I get the following error:
psql: FATAL:  Ident authentication failed for user "wt_admin"


I have spent quite some time searching the net, reading and so on, but
cant seem to find anyting usefull on out how to give my users access to
the database.

All help is appriciated.

Regards
Ronni