I also had the problem that sound-juicer could not mount/access the audio CD. I'm running Debian jessie with Xfce.
The following workaround worked for me: 1. Installed the missing 'gvfs-backends' package manually. 2. Mounting the audio CD with the command 'gvfs-mount cdda://sr0' (as normal user) prior to running sound-juicer. Marco
