Comment 10 for bug 1242567

@Sebastien:
Up until 13.04 version, layout switching was handled by XKB ( http://www.x.org/wiki/XKB/ ) and was set to alt+shift as a default shortcut. Setting this through any DE's graphical keyboard configurator was the equivalent of the following command:
setxkbmap -option grp:switch,grp:alt_shift_toggle,grp_led:scroll us,el

For 13.10 and 14.04, layout switching is primarily handled by i-bus, so Ubuntu's graphical keyboard configurator is not about changing some XKB setting via setxkbmap command, but is about changing an i-bus setting.
The point is that though there may not be a graphical keyboard configurator for XKB anymore, the setxkbmap command still works because it is a part of xorg and xorg is still installed.

So, a common workaround for users is to use a setxkbmap command setting for layout switching. This way, the user avoids the effects of the #1218322 and #1226962 bugs.

The #1218322 bug is now fixed. For the #1226962 bug things are also mainly ok, but there is still a problem with LibreOffice, so there still is a point using a setxkbmap command to set layout switching via XKB.
What is happening is that when changing layouts via the shortcut set by a setxkbmap command, the indicator does not see that a change has been made.

Sorry for the long reply, i hope this is clearer now.