I've write about how to solve alt click on Ubuntu 11.10 when using Blender. But, the solution using gconf-editor can't work on Ubuntu 12.04 with Gnome-Shell. So, i trying to change using another conf editor called dconf-editor and it's work. You must install dconf-editor first with type
sudo apt-get install dconf-tools. Wait the installation for a second, you don't need long time to download because the size of installer is small.
, by Pandu Aji Wirawan