When I had Ubuntu 10.04 Netbook Edition installed on this machine, I used IBus to switch input methods among English, Japanese, and Korean. When I updated to Lubuntu 12.04, however, IBus won't do that. How can I toggle my IME to use Korean and Japanese now?

I have the following apps in my menu: System Tools > IBus, Preferences > Input Method Switcher, and Preferences > Keyboard Input Methods. Clicking on IBus or Input Method Switcher does nothing.