This bug has been fixed by using the following process. Go to: System -> Administration -> Login Window
On the Local tab under "Menu Bar" the option "Show Actions menu" has to be enabled.
this resolves the issue on both the shutdown button screen and on the login/gdm screen.
However this is a fix of the symptoms, the problem appears to be either a theme or gdm theme has the ability to change this setting.
This bug has been fixed by using the following process.
Go to: System -> Administration -> Login Window
On the Local tab under "Menu Bar" the option "Show Actions menu" has to be enabled.
this resolves the issue on both the shutdown button screen and on the login/gdm screen.
However this is a fix of the symptoms, the problem appears to be either a theme or gdm theme has the ability to change this setting.