Palm WebOS: common reasons why sound would play on one device, but not the another?

I'm finishing up my first app on the Palm Pre for a client. During testing I was sad to discover that the sounds, which work fine on my palm, won't play at all on my client's device.

I'm playing sound like so:

    this.objAudioPlayer = new Audio();
this.objAudioPlayer.src =   Mojo.appPath + 'sounds/'+'RID_SND_GAME.mp3';
this.objAudioPlayer.play();

Is there something fishy with this code? What else should I look for?

Ok - to answer my own question...

Apparently, on the Palm WebOS 1.2.1, you can play a sound that isn't part of the .ipk current package, but was part of a previous release. I was hearing phantom sounds on my device because they had previously been installed as part of an earlier release of that program, but the sound files were not included in subsequent releases. So, although I could heard sounds on my device, my client could not because he was just getting the latest checkout, which was missing some required audio files.

I was able to reproduce the client's experience by deleting the app from my device and then doing a fresh palm-install (hmmm, do a clean install before shipping code, seems like I may have heard that advice before).