let me add the output of Nautilus, to help understanding. I start to think I am affected from a slightly different bug, since I don't see any issue in udev in my system. Should I open another bug? Can I bring all the comments and stuff already uploaded here? Thanks
maurizio@bastialaptop:~$ killall nautilus
maurizio@bastialaptop:~$ nautilus &
(nautilus:4473): Eel-CRITICAL **: eel_preferences_get_boolean: assertion `preferences_is_initialized ()' failed
** (nautilus:4473): WARNING **: No marshaller for signature of signal 'UploadFinished'
** (nautilus:4473): WARNING **: No marshaller for signature of signal 'DownloadFinished'
** (nautilus:4473): WARNING **: No marshaller for signature of signal 'ShareCreateError'
Initializing nautilus-gdu extension
(nautilus:4473): GVFS-RemoteVolumeMonitor-WARNING **: invoking List() failed for type GProxyVolumeMonitorGdu: org.freedesktop.DBus.Error.NoReply: Message did not receive a reply (timeout by message bus)
Initializing nautilus-dropbox 0.6.1
Nautilus-Share-Message: Called "net usershare info" but it failed: «net usershare» ha restituito l'errore 255: net usershare: cannot open usershare directory /var/lib/samba/usershares. Error Nessun file o directory
Please ask your system administrator to enable user sharing.