getting service from a local server (v8.2.4)

Hi,

I am new to postgres and having a strange problem. Please help.

I installed postgres v 8.2.4 on a new linux server (not upgrade,
but a virgin install) and created a couple of users. For the
sake of clarity and concreteness, I will call this server S824.
There is another server on the network where S824 resides that
also runs postgres (v 8.1.1). I'll call this server S811.
Postgres on S811 has been running for a ;png time (a year+).

The users I created on S824 are user J and user T. Both users
J and T also have accounts on S811. Here are a few scenarios
that defies my brains (all issued from S824):

a) as user J, I issue "psql testdb"
it behaves the way I want it. It asks me J's password, I
authenticate and I get to psql prompt.
b) as user J, I issue "psql -h S824 testdb"
It behaves exactly like case a). This is also fine.
c) as user T, I issue "psql testdb"
it does NOT behave the way I want it. I want it to behave
like a) and/or b) above. Instead, after authentication, it
offers service from S811 (which also has a database called
testdb).
d) as user T, I issue "psql -h S824 testdb"
it offers the service from S824, which I consider to be
the correct behavior.

So, the problem boils down to c). Can somebody please tell
me what causes c) to go to remote server? And how I can
correct it to behave like user J?

Thank you.

Tena Sakai
tsakai(at)gallo(dot)ucsf(dot)edu