Download resources to the iphone doesnt work...

Hi,

im testing to load external resource data from my server in my unity-iphone-app . If i run that script on the mac, it works great. But if i build the unity-iphone-app, it doesnt work and i get an "SIGBUS" error in xcode. Ive read that this is a null reference. But what is wrong? Would be great to have a look. Thanks

private var asset : GameObject;
public var link  : String = "http://myserver.com/unity/prefab_resource.assetBundle";

private var download : WWW;
private var assetbundle : AssetBundle;

function OnGUI()
{
    if(download == null){
    	if(GUILayout.Button("Load prefab")){ 
    		StartDownload(link);
    	}
    }
    else{
    	if(download.error == null){
    		var progress : float = parseInt(download.progress * 100);
    		GUILayout.Label(progress + "%");

    		if(download.isDone && GUILayout.Button("Unload Resource")){
    			download.Dispose();
    			download = null;
    			assetbundle.Unload(true);
    			assetbundle = null;	
    			Destroy(asset);
    		}
    		else{
    			GUILayout.Label(download.error);	
    		}

    	}
    }	
}

function StartDownload(url : String){
    download = new WWW(url);
    print(download.url);
    yield download;

    asset  = Instantiate(download.assetBundle.mainAsset);
    assetbundle = download.assetBundle;
}

If you press continue in the Xcode debugger and check the console you can see the error. When loading iPhone assests make sure you built them with iPhone unity not regular unity. I have done sucessful asset downloads to iPhone like this.