You can also delete the backup schedules and reboot the unit. Using a USB (especially one that is powered by the Buffalo) I have found very unreliable.
As a suggestion, if yo can afford it, get another Buffalo and set it up as a Backup Unit. Lets say you have an LS120 3TB, get another and call it BuffaloBackup (or what you want) and recreate the same shares, share-for-share. Now, on your main unit create backup plans to do a daily backup (overnight) to the backup unit.
This has a two-fold function; 1) you have a reliable backup and 2) if you rely (as I do) on your NAS box for files, data, work, etc, if the main box dies on you then take it offline and connect to your BuffaloBackup and rename it to the same name as the main working unit and set it's IP to the same as the dead unit and voila, you have a fully functioning system again. No need to recreate shares and link, etc on your PC. Now, get another unit to replace the dead one and that becomes your backup unit.
Pro Tip: Put the Backup Buffalo in a safe place, away from your main kit and if poss, in a different office, etc. That way, if the main unit is damaged by fire, water, theft, the backup is safely tucked away somewhere
Cheers
