PostgreSQL not starting after changing Hostname

Hi everybody,

I'm quite a new guy on the Linux World and I have a tremendous problem
with ProstgreSQL, the problem is that after changing the name of the
host (via Network Manager in KDE) and restarting the server, the
PosgreSQL (and other things like XWindow) stopped working.

I tried to restore the original name via changing the "/etc/hosts" and
"/etc/sysconfig/network" files and running the "/bin/hostname -s"
command but it didn't resolve my problem.

The server is running Linux RedHat 7.2 and PostgreSQL 7.2

Any ideas?