Dead-end in PostgreSQL 8.0 fresh installation (while upgrading doesn't get anywhere)

Hi again...

I tried to solve my PostgreSQL cluster problem like Michael Fuhr and
Lonni Friedman helps me, but I didn't get it work. So I figured out that
if I do an fresh installation and removed the PostgreSQL completely
(even those JDBC and PL -drivers - everything) and be sure that it is
completely removed. Then I installed it again with rpm -Uhv command and
start to proceed like the manuals tells me, but now I'm in dead-end:
initdb fails because postgres program was not found. How this could be
happened? I did not removed the postgres user because I thought that is
not needed to do. Initdb returns following fail:

# su postgres
bash-3.00$ initdb -D=/var/lib/pgsql/data/
fgets failure: Success
The program "postgres" is needed by initdb but was not found in the
same directory as "/usr/bin/initdb".
Check your installation.

I did check that file postgres really is in /usr/bin -folder.

How should I proceed now?
--
Jarkko Elfving <jarelf(at)ebaana(dot)net>