Hopefully someone knows what's going on.

I often connect my Nexus S 4G to my PC to manage my music files.
I've created several playlists, but for the 3rd time in the month, after removing the connection and going to the playlists, they are there, but they are now empty and I have add the music files again.

Any idea what's going on? And can I save the playlists somewhere else as a backup?

Sent from my Nexus S 4G using Tapatalk