Sorry for the delay topdog.
I've followed again the tuto in a virtual machine on a fresh debian etch install.
After step 9, the auth via ssh was not working anyway. But, once logged in webmin, this one warned me that two files was mismatching. Then, I selected the proposed solution : auto repair the involved files. Then, auth was working.
I decided to compare the two config files (physical server Vs virtual server) /etc/pam_ldap.conf and found this difference :
* physical contains : "uri ldapi:///127.0.0.1"
* virtual contains : "uri ldap://127.0.0.1"
So, by updating the physical server config file, I resolved my authentification problem.
I've still an error reported in /var/log/auth.log (see the first line of the following three) when I'm logging in via ssh :
(pam_unix) authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=192.168.1.12 user=david
Accepted password for david from 192.168.1.12 port 48172 ssh2
(pam_unix) session opened for user david by (uid=0)
So, what's wrong with this config????
And why "uid=0" in the auth.log file???
Thank you in advance