Really? Not in this thread? It's been discussed in several places in this thread and the guide even uses screen to accomplish the task of doing multiple things in the same terminal window. Using screen via SSH is the answer to the question asked.
The method used in that linked guide is like using a hammer to drive in a screw. It will probably work but it's not the best way to go about things.
It was a problem of permissions with X server. It seems, that Ubuntu default policy is opener than Debian's. I was not possible for me to stablish a connection to X server out of the main screen.
In the linked method, what is really interesting to me is:
Next editetc/gdm/Init/Default and add the following code just before the exit 0.
Code:
xhost +
chmod uog+rwdev/dri/card*