Settings/System Settings/USB Mode. Change it from MTP to MSC. Or from MSC to MTP.
Your computer can only see one mode at a time, so if you transferred some songs with Windows Media Player (via MTP) and others by drag-and-drop (via MSC), your computer will not see all of them at one. The Fuze knows all, sees all.
It may have been on Auto Detect. Auto goes to MTP if your computer has Windows Media Player 10 or above. It goes to MSC if you don’t (or if you have a non-Windows operating system). So if you were transferring songs from two different computers, it may have used different modes without you noticing.
You need MTP for files from subscription services like Napster or Rhapsody. Since I don’t use those, I leave it on MSC, which is more universal. But it’s up to you.
