MIXO can't play tracks with DRM protection so whenever it comes across an m4p file, it just hangs trying to load forever. If listening to a playlist this stops playback and causes the user to have to manually skip to the next file. It might be nice to display a warning that this filetype can't be played due to the DRM protection, and skip to the next song after a few seconds to keep the listening session going. Maybe with a setting to toggle/ignore the warnings as well.