Android :: Media Player Not Playing Sounds On Droid X

I have some pretty simple Soundboard applications on the Android Market that work flawless on an LG Ally, the Motorola Droid, and the Nexus One, but I recently received an e-mail from a user with the Motorola DroidX claiming that most of the sounds do not work. I've exchanged a few e-mails with him. He claims the Soundboard is the only application running, and he's double checked to make sure that the Media Volume wasn't set to minimum. I really don't have access to one either to play around with. The application isn't doing anything cosmic to play the sounds. Below is a code snippet. Any insights into what might be causing the hang up are greatly appreciated.

public void play(Sample sample) {
Log.v(TAG, "Playing: " + getString(sample.getButtonTextResId()) + " (" + sample.getSoundResId() + ")");
if (mPlayer != null) { mPlayer.stop(); mPlayer.release();
} MediaPlayer player = MediaPlayer.create(this, sample.getSoundResId());
mPlayer = player; if (player != null) { player.setVolume(1.0f, 1.0f);
player.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override public void onCompletion(MediaPlayer mp) { mp.release();
mPlayer = null; } } ); player.start(); } }