I just updated 14.04 to latest patches using the GUI: software update. After that, a restart was required, and now cannot log into any of my accounts. I am sure the passwrds are all correct, it just bounces me back to the same login screen (as opposed to when I really type a bad passwd, then ubuntu states that "Incorrect Passwd"). The only other thing I did was change my background image.
Information from my auth.log:
Apr 29 16:00:56 jj-home lightdm: pam_unix(lightdm-greeter:session): session closed for user lightdm gnome-keyring-daemon[2449]: couldn't set environment variable in session: The name of the org.gnone.SessionManager was not provided by any .service files gnome-keyring-daemon[2449]: g_dbus_connection_real_closed: Remote peer vanished with error: Underlying GIOStream returned 0 bytes on an async read (g-io-error-quark, 0). Exiting. lightdm: pam_unix(lightdm-greeter:session): session closed for user lightdm