Try this, copied from somewhere on the forum, not sure where
Backup XBMC settings:
SSH into the Pi.
Go to /home/pi
Run the following command:
tar -czf xbmc-backup.tar.gz .xbmc
Ftp into the Pi and copy the xmbc-backup.tar.gz file away from Raspberry Pi
Put settings back:
copy file back to /home/pi
Run command:
tar -xzf xbmc-backup.tar.gz