Can't login after lock screen, how to fix the /etc/pam.d/common-auth?

Question

I got mysteriously locked out of my ubuntu 10.04 but got it solved on question How to fix a broken login in ubuntu 10.04?

Yet a big annoyance remains, if lock my screen and return, the authentication window there still won't accept my password (even though I can ctrl+alt+F1 and login in the console). I have deactivated all auto-locking configuration but that's not a long term solution for me, I though that by tinkering with /etc/pam.d/common-auth I would be able to solve the last problem but I have been unable.

Below is my current common-auth file, is there anything wrong with it? I though this was Ubuntu's default.

#
# /etc/pam.d/common-auth - authentication settings common to all services
#
# This file is included from other service-specific PAM config files,
# and should contain a list of the authentication modules that define
# the central authentication scheme for use on the system
# (e.g., /etc/shadow, LDAP, Kerberos, etc.).  The default is to use the
# traditional Unix authentication mechanisms.
#
# As of pam 1.0.1-6, this file is managed by pam-auth-update by default.
# To take advantage of this, it is recommended that you configure any
# local modules either before or after the default block, and use
# pam-auth-update to manage selection of other modules.  See
# pam-auth-update(8) for details.

# here are the per-package modules (the "Primary" block)
auth required pam_shells.so 
auth required pam_nologin.so 
auth  [success=2 new_authtok_reqd=2 ignore=ignore default=bad] pam_unix.so likeauth nullok_secure try_first_pass
auth  [success=1 default=ignore] pam_unix.so nullok_secure try_first_pass
# here's the fallback if no module succeeds
auth requisite   pam_deny.so
# prime the stack with a positive return value if there isn't one already;
# this avoids us returning an error just because nothing sets a success code
# since the modules above will each just jump around
auth required   pam_permit.so
# and here are more per-package modules (the "Additional" block)
auth optional pam_ecryptfs.so unwrap
# end of pam-auth-update config