How to handle ObservableCollection<> result from a parallelized Task in MVVM?

I am gathering data in a separate Task and I want to data bind the result to a GUI component using an ObservableCollection<>. So my code goes something like this:

private Obser开发者_StackOverflowvableCollection<MyItem> _items;
public ObservableCollection<MyItem> Items
{
  get { return _items; }
  set
  {
    if (_items.Equals(value))
    {
      return;
    }
    _items = value;
    RaisePropertyChanged("Items");
  }
}

private void LoadData()
{
  Task task = Task.Factory.StartNew(() =>
  {
    ObservableCollection<MyItem> itms = _htmlParser.FetchData(...);

    Dispatcher.CurrentDispatcher.Invoke((Action)delegate
    {
      Items = itms;
    });
  });
}

The data is fetched from a component doing some HTTP requests. The error I am getting is:

Must create DependencySource on same Thread as the DependencyObject.

I am using the MVVM Light toolkit framework. I also tried to send the result as a message, but that ended up in the same error message. Any ideas or pointers?

EDIT: Here's the issue:

public class MyItem
{
  public string Id { get; set; }
  public string Name { get; set; }
  public BitmapImage Image { get; set; }  // <--- A big No No because it inherits from the DependencyObject
  public Uri Uri { get; set; }
}

I changed the BitmapImage to a byte[] data type.

Can you try to replace the Dispatcher.CurrentDispatcher into Application.Current.Dispatcher not sure about this though

The exception you're getting ("Must create DependencySource on same Thread as the DependencyObject") indicates that something's being created on a background thread and used on the UI thread. Are there any UI controls being created and stored in the collection for use by the UI?

I see that the ObservableCollection itself is being created on a background thread, but I don't think that's the issue -- unfortunately I'm not in the office to code and confirm that.