Program: 7258
Project: 7258
Buggy source:
public void update(int delta){
  if (enabled) {
    if (musicPlaying == null) {
      musicDelay-=delta;
      if (musicDelay <= 0) {
        musicPlaying=music.get((int)(Math.random() * music.size()));
        musicPlaying.playAsMusic(1.0f,1.0f,false);
        soundStore.setSoundVolume(0.75f);
      }
    }
 else     if (!soundStore.isMusicPlaying()) {
      musicPlaying.stop();
      musicDelay=(int)(Math.random() * 90000) + 30000;
      musicPlaying=null;
      soundStore.setSoundVolume(1.0f);
    }
    if (ambientMusic == null) {
      ambientMusicDelay-=delta;
      if (ambientMusicDelay <= 0) {
        ambientMusicPlaying=ambientMusic.get((int)(Math.random() * ambientMusic.size()));
        ambientMusicPlaying.playAsSoundEffect(1.0f,(float)Math.random() * 0.2f + 1f,false);
      }
    }
 else     if (!ambientMusicPlaying.isPlaying()) {
      ambientMusicPlaying.stop();
      ambientMusicDelay=(int)(Math.random() * 6000) + 1000;
      ambientMusicPlaying=null;
    }
    if (ambientNoisePlaying[0] == null) {
      ambientNoiseDelay[0]-=delta;
      if (ambientNoiseDelay[0] <= 0) {
        ambientNoisePlaying[0]=ambientNoise.get((int)(Math.random() * ambientNoise.size()));
        ambientNoisePlaying[0].playAsSoundEffect(1.0f,(float)Math.random() * 0.2f + 1f,false);
      }
    }
 else     if (!ambientNoisePlaying[0].isPlaying()) {
      ambientNoisePlaying[0].stop();
      ambientNoiseDelay[0]=(int)(Math.random() * 16000) + 1000;
      ambientNoisePlaying[0]=null;
    }
    if (ambientNoisePlaying[1] == null) {
      ambientNoiseDelay[1]-=delta;
      if (ambientNoiseDelay[1] <= 0) {
        ambientNoisePlaying[1]=ambientNoise.get((int)(Math.random() * ambientNoise.size()));
        ambientNoisePlaying[1].playAsSoundEffect(1.0f,(float)Math.random() * 0.2f + 1f,false);
      }
    }
 else     if (!ambientNoisePlaying[1].isPlaying()) {
      ambientNoisePlaying[1].stop();
      ambientNoiseDelay[1]=(int)(Math.random() * 16000) + 1000;
      ambientNoisePlaying[1]=null;
    }
    soundStore.poll(delta);
  }
}

Fixed version (ground truth):
public void update(int delta){
  if (enabled) {
    if (musicPlaying == null) {
      musicDelay-=delta;
      if (musicDelay <= 0) {
        musicPlaying=music.get((int)(Math.random() * music.size()));
        musicPlaying.playAsMusic(1.0f,1.0f,false);
        soundStore.setSoundVolume(0.75f);
      }
    }
 else     if (!soundStore.isMusicPlaying()) {
      musicPlaying.stop();
      musicDelay=(int)(Math.random() * 90000) + 30000;
      musicPlaying=null;
      soundStore.setSoundVolume(1.0f);
    }
    if (ambientMusicPlaying == null) {
      ambientMusicDelay-=delta;
      if (ambientMusicDelay <= 0) {
        ambientMusicPlaying=ambientMusic.get((int)(Math.random() * ambientMusic.size()));
        ambientMusicPlaying.playAsSoundEffect(1.0f,(float)Math.random() * 0.2f + 1f,false);
      }
    }
 else     if (!ambientMusicPlaying.isPlaying()) {
      ambientMusicPlaying.stop();
      ambientMusicDelay=(int)(Math.random() * 6000) + 1000;
      ambientMusicPlaying=null;
    }
    if (ambientNoisePlaying[0] == null) {
      ambientNoiseDelay[0]-=delta;
      if (ambientNoiseDelay[0] <= 0) {
        ambientNoisePlaying[0]=ambientNoise.get((int)(Math.random() * ambientNoise.size()));
        ambientNoisePlaying[0].playAsSoundEffect(1.0f,(float)Math.random() * 0.2f + 1f,false);
      }
    }
 else     if (!ambientNoisePlaying[0].isPlaying()) {
      ambientNoisePlaying[0].stop();
      ambientNoiseDelay[0]=(int)(Math.random() * 16000) + 1000;
      ambientNoisePlaying[0]=null;
    }
    if (ambientNoisePlaying[1] == null) {
      ambientNoiseDelay[1]-=delta;
      if (ambientNoiseDelay[1] <= 0) {
        ambientNoisePlaying[1]=ambientNoise.get((int)(Math.random() * ambientNoise.size()));
        ambientNoisePlaying[1].playAsSoundEffect(1.0f,(float)Math.random() * 0.2f + 1f,false);
      }
    }
 else     if (!ambientNoisePlaying[1].isPlaying()) {
      ambientNoisePlaying[1].stop();
      ambientNoiseDelay[1]=(int)(Math.random() * 16000) + 1000;
      ambientNoisePlaying[1]=null;
    }
    soundStore.poll(delta);
  }
}