Where's the “log out” option after clicking the power icon?

Question

So the documentation says:

To log out or switch users, click the power icon on the top bar and select the appropriate option.

However, I cannot see the "log out" option. All I see are:

• Lock Screen
• Switch from ubuntu
• Suspend
• Restart...
• Shut Down
• System settings

I managed to log out via a terminal command. Any way to log out via the Unity GUI or add this option to the power icon menu?

update: I'm running from a live USB.

Answer 1

• Open gconf-editor (press Alt + F2, type gconf-editor, press Enter)

• Navigate to /apps/indicator-session/

• Make sure none of the checkboxes on the right pane are ticked:

  

However, it would be interesting to know why that happened (maybe worth reporting a bug).