While using the Android SoundCloud application on my Samsung Galaxy Note 2, I have noticed before and most recently that not all tracks that I add to a playlist actually stick. Most might do however there comes a point where any added tracks do not stay on the playlist added beyond that logged in session as far as I'm aware. For instance, my Mobile playlist which I specifically created having known about this issue did have some 11 or so tracks the last I added. However, only 8 have stuck. I can only confirm the latest occurrence as the 2 previous were based on a gut feeling that tracks were missing.