I have Ubuntu 13.04 32-bit with GNOME 3.8.2, and Unity installed too.
Two languages are selected as input sources - English(US) and Russian.
Keyboard shortcut to change input methods is set.
Indicator in top notification panel works well.
The problem is that changing input method by keybinding does not work properly - it changes only the indicator in the top panel and does not affect typing from keyboard. It doesn't matter which language is selected through keyboard shortcut, typing from keyboard brings symbols only from English input method.
But, if I change language from panel (from EN to RU, by example), everything works okay and I can type Russian symbols. Then I again change language, now by keybind (to EN), it works too, but only once, next usage of keybind does not affect input method, leaving only English input.
In Unity everything works, without any problems.