lost focus when switching input source

I use ibus as IME in my ubuntu box, as I will need to input both English and Chinese characters. guake used to work fine with ibus, I can switch back and forth input method in a guake shell without losing focus.

With a recent update, every time I do Ctrl+Space to switch the input method, guake will lost focus and auto hide itself (I set in the preference, auto hide when losing focus), which is very annoying.

It's not a hotkey problem. I changed the "Ctrl+Space" to other key combination for input method switching, and the same issue happened when I switch the input method.

Can someone advise me what could be the course of the problem?

BTW, don't know whether it is helpful for your debuging. When I launch the guake at front end, I see a lot of warning like:
(guake:8977): libglade-WARNING **: unknown attribute `swapped' for .