after remove zeitgeist, there is no unity in Ubuntu
Use this to Remove/Uninstall Compiz Unity:
sudo apt-get remove compizconfig-settings-manager
sudo apt-get remove compiz-fusion-plugins-extra
sudo apt-get remove compiz-plugins-extra
sudo apt-get purge compiz*
Then to Re-install Compiz Unity use:
sudo apt-get install unity-2d
sudo apt-get install ubuntu-desktop
sudo apt-get install ubuntu-desktop-2d
sudo apt-get install compizconfig-settings-manager
sudo apt-get install xserver-xgl
sudo apt-get install emerald
sudo apt-get install compiz-fusion-plugins-extra
sudo apt-get install git compiz-plugins-extra
sudo apt-get install compiz-plugins-extra
sudo apt-get install unity