IDENT authentication problem

This is what I did:

1: I reinstalled postgresql RPMs from scratch (I removed all the logs,
data files, backup files)

2: su root

3: su postgres

4: psql template1

And here I got the error message:

psql: FATAL 1:  IDENT authentication failed for user "foobar"

User "foobar" was an old user I created for the database *before* I
wiped out everything and reinstalled the RPMs. It is already gone from
my /etc/password. (since I was using IDENT)

What could have gone wrong? I must have left the trace of user foobar
somewhere in my system but I couldn't find it.

Thanks


-- 
Wei Weng
Network Software Engineer
KenCast Inc.