Comment 33 for bug 553200

I think the bug is directly connected to the password authentication in gdm.
I deactivated passwords in gdm (adding "auth sufficient pam_listfile.so item=user sense=allow file=/etc/gdm/nopassusers.txt onerr=fail" in /etc/pam.d/gdm file + my user name in /etc/gdm/nopassusers.txt) ; and I can login & logout perfectly in gdm