installation problem -please help

Hi,
I am installing postgresql 7.0.3 again from scratch on my new PC. I have got
stuck again at the the initdb step. I cannot   remember how I got it to run
last time!! But it has been one  recurrent problem for me. I wonder why? I
want a smooth installation :-)

Here you are
[root(at)localhost bin] # mkdir /usr/local/pgsql/data
[root(at)localhost bin] # chown -R postgres:postgres /usr/local/pgsql/data
[root(at)localhost bin]# su postgres
[postgres(at)localhost bin]$ cd /usr/local/pgsql/bin
[postgres(at)localhost bin]$ ./initdb /usr/local/pgsql/data
This database system will be initialized with username "postgres".
This user will own all the data files and must also own the server process.

Creating database system directory /usr/local/pgsql/data
Creating database system directory /usr/local/pgsql/data/base
Creating database XLOG directory /usr/local/pgsql/data/pg_xlog
Creating template database in /usr/local/pgsql/data/base/template1
Creating global relations in /usr/local/pgsql/data/base
Adding template1 database to pg_database
./initdb: /root/tmp/initdb.1626: Permission denied
./initdb: /root/tmp/initdb.1626: Permission denied
./initdb: /root/tmp/initdb.1626: Permission denied
./initdb: /root/tmp/initdb.1626: Permission denied
rm: cannot remove `/root/tmp/initdb.1626': Permission denied

initdb failed.
Removing /usr/local/pgsql/data.
Removing temp file /root/tmp/initdb.1626.
rm: cannot remove `/root/tmp/initdb.1626': Permission denied
Failed.

:-(

I tried chown -R postgres:postgres /root/tmp too
No luck!
Thanks for your help!

Nandalal