Question regarding "Part 4: File access and pickers" of the "Windows Store apps using C#/VB and XAML"

In this part of the tutorial, an image is retrieved from a File Picker and added to the application's Most Recently Used List so it can be saved and retrieve when the app is suspended or terminated. The problem I am running into is the image is not getting restored when I re-launch the app.

I tracked the problem down to the navigationHelper_LoadState method.

In the navigationHelper_LoadState method, e.PageState is always coming in as Null. Thus the page cannot restore the Image saved to the MostRecentlyUsedList.

Using the debugger, I can see that e.PageState is getting the mruToken key and value saved to it's dictionary when I navigate away from the page, but when I navigate back to the page, e.PageState is Null.

        private async void navigationHelper_LoadState(object sender, LoadStateEventArgs e)
        {
            if (e.PageState != null && e.PageState.ContainsKey("mruToken"))
            {
                object value = null;
                if (e.PageState.TryGetValue("mruToken", out value))
                {
                    if (value != null)
                    {
                        mruToken = value.ToString();
                        // open the file
                        Windows.Storage.StorageFile file =
                            await Windows.Storage.AccessCache.StorageApplicationPermissions.MostRecentlyUsedList.GetFileAsync(mruToken);

                        if (file != null)
                        {
                            Windows.Storage.Streams.IRandomAccessStream fileStream =
                                await file.OpenAsync(Windows.Storage.FileAccessMode.Read);

                            Windows.UI.Xaml.Media.Imaging.BitmapImage bitmapImage =
                                new Windows.UI.Xaml.Media.Imaging.BitmapImage();

                            bitmapImage.SetSource(fileStream);
                            displayImage.Source = bitmapImage;
                            this.DataContext = file;
                        }
                    }
                }
            }
        }