About a couple of weeks ago I transferred roughly 1GB of music to my Droid. Most of the file were bought from iTunes and were .mp4/.m4a. They played fine until yesterday, they just all of a sudden stopped playing. I've put iTunes songs on my phone before and this is the first time it's happened. The music player I was using was Music Mod, but they don't play on the stock player, Mixzing, or Cubed. Any suggestions?