sublimetext.com/docs/3/column_selection.html

In Ubuntu 12.10, the keys just change workspaces, even when the focus is on st2/st3

Linux Ctrl + Alt + Up Ctrl + Alt + Down

You need to either disable these keyboard shortcuts in Ubuntu’s preferences panel or remap them to different keys in Sublime.

With KDE, Gnome, XFCE, and everybody’s pet window manager, standard keyboard shortcuts on Linux are a complete mess.