postgresql jdbc connect via hostname instead of just ip

Hi all,
I'm a bit new to postgresql.  I've been able to
configure the database and the jdbc interface
successfully.  I interface via PAM (krb5) and that
works OK in the pg_hba.conf file. I've added the -i
option to the postmaster startup script service (using
binary RPMs on Fedora Core 4) for tcp connections
(default port 5432).

The only way I can connect to the database via JDBC
seems to be by IP address (both locally and on another
system allowed by the pg_hba.conf file).

jdbc:postgresql://theipaddressofdatabaseserver/mydatabase

I'd like to be able to connect to the database this
way using a DNS name / computer host name.  The
specific error I recieve is on the lines of no route
to host.

I'm sure I'm just missing a simple setting somewhere.
Can anyone point me in the right direction?

pg_hba.conf
host mydatabase all 127.0.0.1/32 pam
host mydatabase all theipsubnet/24 pam

Many thanks,
Jonathan