I had this problem with sbackup 0.11.4 on Lubuntu, installed as Ubuntu 12.10 with lubuntu-core package installed. When
sudo sbackupis run, even with
--legacy-, it still gives plenty of errors and notably, the message "No desktop session found".
Strangely, scheduled backups work though. But when I tried instead:
that seems to work.
The bug might be because Lubuntu doesn't have 'gnome-session' or 'x-session-manager' running. Instead, it uses 'lxsession'.