I am following the element14 instructions to install a PiFace 2. When I enter this code " sudo nano /etc/modprobe.d/raspi-blacklist.conf ¨ I get an empty window as if I am going to create raspi-blacklist.conf. I have to exit out of there and can go no further. I followed all instructions with no problem to get to that point. I even started over to no avail. Anybody know what to do now?