I got Ubuntu 13.04 32-bit, with Gnome 3.8.2, and Unity installed too. Two languages selected as input sources - English(US) and Russian. Keybind to change input methods is set and works okay. Indicator in Gnome top notification panel works good too.
The problem: Changing input method by keybind does not work properly - it changes only indicator in top panel and does not affect typing from keyboard. Does not matter, which language is selected through keybind, 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. Sorry for bad English =(