Well, despite the board has the default baser address (0), only if I chose the last PiFace Digital (from top to bottom), I manage to change the output (LED On/Off) so I imagine that the bottom PiFace is address 0. Any other wont change the LED. A way to identify which one is available would be great.
I did what you suggest (change from GPIO to PiFace on the left), it moved to PiFace on the left but did not work, says Unreachable. I did a reboot and, Puf, all the widgests disapperead. Also if I try to create one, most of the times it gives an error and when, finally, it does create and appears in the Dashboard, again, Unreachable.
Also, when I try to add a Widget under Actuators, it returns an error stating Failed to add Sensor but I am clearly under Actuators.
Any ideas ?