U3DXT AVAudioPlayer

Hi, I'm trying to use the AVAudioPlayer class of U3DXT but after creating a new instance of the AVAudioPlayer and calling Play() I get the following error:

U3DXTException: Cached object (null) is invalid at U3DXT.iOS.Native.Internals._CallbackCache._ThrowException (System.String str) [0x00000] in :0 at (wrapper native-to-managed) U3DXT.iOS.Native.Internals._CallbackCache:_ThrowException (intptr) at U3DXT.iOS.Native.AVFoundation.AVAudioPlayer.Play ()

The code that causes this error is as follows :

 #pragma strict
 import System.IO;
 import U3DXT.Core;
 import U3DXT.iOS.MediaPlayer;
 import U3DXT.iOS.Native.MediaPlayer;
 import U3DXT.iOS.Native.Foundation;
 import U3DXT.Utils;
 import U3DXT.iOS.Native.AVFoundation;
 
 var query : MPMediaQuery;
 var mediaItem : MPMediaItem;
 var theError : NSError;
 var songURL : NSURL;
 var theAudioPlayer : AVAudioPlayer;
 
 function Start () {
     
     theError = new NSError();
     query = new MPMediaQuery.SongsQuery();
     mediaItem = query.items[0] as MPMediaItem;
     songURL = new NSURL(mediaItem.PropertyAssetURL);
     
     theAudioPlayer = new AVAudioPlayer(songURL, theError);
     theAudioPlayer.Play();
 }

//Changing the last two lines to :

 theAudioPlayer = new AVAudioPlayer();
 Debug.Log("Volume : " + theAudioPlayer.volume);

Results in the following in XCode :

 0x17e0e46:  vmov   d8, r0, r0    <Thread 1: EXC_BAD_ACCESS(code=1, address=0x1c)
 
 in Thread 1 UP_AVAudioPlayer_get_volume

Any help is appreciated,

Thanks!
Brandon