Comment 11 for bug 1356548

I thought being hit by this bug while having the same 'ascii' codec error message traing to restore a succesfully backed up file with accented characters in it's name.
However it proved to be a locale related problem I discovered while chasing an apparently unrelated issue of having English menu items instead of French ones in another package (found in http://doc.ubuntu-fr.org/cinelerra).
For me the following actions solved the duplicity file naming issue:
1. Add the following line in /var/lib/locales/supported.d/local :
   fr_CH.UTF-8 UTF-8
2. Reconfigure the locales
   sudo dpkg-reconfigure locales

Now th subject file is successfully restored.