Change input method, get extreme lag

[a p]

I was told here to report bug:
http://askubuntu.com/questions/343494/

I'm running 12.04 LTS, Xubuntu flavor (x64). IBus 1.4.1-3ubuntu1, installed language is Japanese anthy. IBus starts with the session (ibus-daemon -drx) and is selected under Language Support (I've tried it without these and the problem is the same). I select an input method through a keyboard shortcut, the notification icon, the floating menu, or manually through IBus preferences, in decreasing order of lag. I would expect it to change in perhaps 10 seconds, but it takes 5 minutes (average) to an hour. When it's running I have no problems, but it doesn't want to change back to default either.

[a p (amalka-palka)]

OK, I've been playing around more, and to get it to switch semi-quickly (~30s or less) you can change language via floating bar, and then (with Focus Follows Mouse on) move your mouse back and forth between an input window (e.g. word processor) and any other window (input, no input, whatever) - perhaps IBus is having big problems with ID'ing input windows? I don't know...