Most of the music I listen to is through Spotify, but of course there are tracks that I download independently. In order to not have to use two different mobile players, I add files from my hard-drive to my Spotify playlists. I then make certain playlists available offline on my phone for music on the go. This works fine, HOWEVER...if I play Spotify on my computer, then open Spotify on my phone and choose the "continue playing music on your computer" option, it will from then on grey out all my non-spotify files contained in the "available offline" playlists on my phone. This is insainly annoying as it seems the only way to get them back is to uncheck the "available offline" button and recheck it...having to re-sync the entire playlist (I listen to a lot of sets so this can take quite a bit of time). WHY IS THIS HAPPENING?