Comment 25 for bug 625239

what happen after few tweaks:

- compiz package installed, system/prefs/appearance/visual effects: no visual effects
- system/prefs/compizconfig: disabled all "effects" & "extras" settings & session manager (into utils)

on next reboot: first login always fail, second is fine. Got these errors logged:

 polkitd(authority=local): Unregistered Authentication Agent for session /org/freedesktop/ConsoleKit/Session3 (system bus name :1.37, object path /org/gnome/PolicyKit1/AuthenticationAgent, locale fr_FR.utf8)
 gdm-session-worker[1562]: pam_succeed_if(gdm:auth): requirement "user ingroup nopasswdlogin" not met by user "oem"
 gdm-session-worker[1562]: pam_unix(gdm:auth): conversation failed
 gdm-session-worker[1562]: pam_unix(gdm:auth): auth could not identify password for [oem]
 gdm-session-worker[1562]: pam_winbind(gdm:auth): getting password (0x00000388)
 gdm-session-worker[1562]: pam_winbind(gdm:auth): Could not retrieve user's password
 gdm-session-worker[2716]: pam_succeed_if(gdm:auth): requirement "user ingroup nopasswdlogin" not met by user "oem"
 gdm-session-worker[2716]: pam_unix(gdm:session): session opened for user oem by (uid=0)
 gdm-session-worker[2716]: pam_ck_connector(gdm:session): nox11 mode, ignoring PAM_TTY :0