Double entry in local scan

Each time I perform a local scan, files are added twice. i.e., after having added an album with 11 tracks:

Running "/usr/bin/mopidy --config /usr/share/mopidy/conf.d:/etc/mopidy/mopidy.conf local scan" as user mopidy
INFO     Starting Mopidy 2.2.1
INFO     Loading config from builtin defaults
INFO     Loading config from /etc/mopidy/mopidy.conf
INFO     Loading config from command line options
INFO     Enabled extensions: iris, mpd, alsamixer, http, stream, spotify_tunigo, m3u, scrobbler, podcast-itunes, internetarchive, softwaremixer, local-sqlite, file, local-images, dirble, podcast, local, tunein
INFO     Found 977 files in media_dir.
INFO     Checking 930 tracks from library.
INFO     Removing 0 missing tracks.
INFO     Found 22 tracks which need to be updated.
INFO     Scanning...
INFO     Scanned 22 of 22 files in 0s.
INFO     Cleaning up image directory
INFO     Done scanning.

And in the “Albums” view I have this album with 22 tracks listed, each one doubled.

Sorry, of course not a mopidy issue…
I have found the problem here: files are stored in a usb key. But the key is mounted twice, one in /music/usb0 and another one in /music/usb1 due to a previous installation of udisk!!

Please remove.