Migrating from 7.0RC1 to 7.0.2 and initdb

Hello.

A few days ago, I tried to migrate from v7.0RC1 to 7.0.2. Since major version
number doesn't change, I just stopped postmaster, installed the new RPM (I work
under Redhat 6.1) and started the new postmaster.
I got an error such as 'System catalog version changed, you should use initdb'.
Well, I watched at initdb manpage, and then tried:
    initdb --template
This should just rebuild template1 and don't delete anything. But:
    [Error...]
    Removing /var/lib/pgsql...
Argh!!

One restoration later, I used initdb --template --noclean and it appeared that
the file pg_control must be deleted before using initdb...

And postgresql-backup didn't accept to do a backup because of the version
number.

Two questions?
1) Why --noclean isn't implicit?
2) Why initdb doesn't delete pg_control automatically (at least ask for
deletion) when needed instead of returning an error and burning all the
databases ?

Regards.

Guillaume Perréal - Stagiaire MIAG
Cemagref (URH), Lyon, France
Tél: (+33) 4.72.20.87.64