initdb causes Segmentation fault

I'm running ubuntu 8.04 on

a Linux 2.6.24-22-generic #1 SMP Mon Nov 24 19:35:06 UTC 2008 x86_64 GNU/Linux
machine.

there was same porblem with preinstalation of progres and superuser.
So I tried to solve it by reinstall postgres 8.3 with apt-get after removing it with
sudo apt-get --purge remove $(aptitude search postgres|awk '/^i/{gsub(/^i.../,"");print}'|awk '{print $1}')

but results in segmentation fault when it comes to call initdb.

I downloaded PostgreSQL 8.3.6 single click installer which had also problems with initialization.

So I downloaded the source of PostgreSQL 8.3.6 and compiled and installed it.
But again when I have to run

/usr/local/pgsql/bin/initdb -D /usr/local/pgsql/data

it ends with Segmentation fault.

output of strace:

12050 --- SIGCHLD (Child exited) @ 0 (0) ---
12050 munmap(0x7f062d3d7000, 4096) = 0
12050 geteuid() = 1000
12050 open("/etc/passwd", O_RDONLY|0x80000 /* O_??? */) = -1 EACCES (Permission denied)
12050 geteuid() = 1000
12050 --- SIGSEGV (Segmentation fault) @ 0 (0) ---
12050 +++ killed by SIGSEGV +++

thx in advance,
Haluk