Unexpected error while saving network settings

[washburn_it]

Hi,

I'm a beginner with XBian and, generally speaking, with the Raspberry but I was able, following various sources on the internet, to succesfully configure RaspBian to use the ethernet interface and activate XRDP through which I can connect to it via RDP from my Windows 7 pc.
Yesterday I went to buy a new SD card where I installed XBian, activated the video composite output (I don't have an HDMI monitor at the moment) and succesfully booted.
Since I would like to "drive" XBian through my smartphone (XBMC app) I went to the network configuration menu to set a static IP configuration.
When I saved the settings a small popup on the lower right corner appeared reporting "an unexpected error occurred" and everything switched to "DHCP".
I tried several times but the result was the same.
So I changed the SD card and booted with RaspBIAN, put the SD card to an USB reader and mounted on RaspBIAN.
I then edited the file "interfaces" in the "/root/@/etc/network" adding the same lines of the "interfaces" of the RaspBIAN, saved the file and closed everything.
I booted then with XBian but when I went to the network configuration menu everything was set as default (DHCP).
Did I write in the wrong file? Why that "unexpected error"?
Thank you, regards.

Roberto