Amarok isn't behaving properly and a search via Google shows many who have the same issue. Basically, Amarok plays one song on the playlist and then stops. Most of the issues I saw during my search points to the phonon backend.
So I fired up GSlapt and looked for phonon and find this (see attached).
So my question is, which backend should be installed? The unchecked phonon-xine-backend is larger than the installed version.