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.
After install it you can run it from terminal with type
Go to org > gnome > desktop > wm > preferences. The default value for mouse-button-modifier is
, change it to
After do that, try to log out and log in back. I hope gconf-editor can help you to make alt click on Blender work when using ubuntu desktop. Because this tool really helpfull for 3D modelling. Thank for tips from UbuntuGuide