Thats' just it, I've tested on 3 different tumbleweed installs, one plain, one with GNOME:Factory repo in plus, and one with GNOME:Next (GNOME 3.17.x), and it just works for me on all of them. To make it clear, what type of copy/paste are we talking about here? ctrl+c / shift+ctrl+v or highlight/middleclick? Are you able to paste into gedit? Meaning is it just gnome-terminal you can not make it work for you?