You may want to take a look here: http://code.google.com/p/ibus/wiki
sudo apt-get update
sudo apt-get install ibus-gtk ibus-qt4 ibus-pinyin ibus-pinyin-db-open-phrase
I have also installed packages for ibus-chewing - as I noticed the name of chapter on ibus site
then
im-switch -s ibus
Logout and re-login
works like a charm 
good luck!