title: BackgroundWorker in Silverlight ViewModel
body: <p>I have a TabControl in a Silverlight View and I'm loading Tabs by binding its ItemsSource to a TabItems ObservableCollection in my ViewModel.</p>
  
  <p>To open a new tab, it takes a little while to create it and load it and I want to run a BusyIndicator meanwhile.</p>
  
  <p>As they are created and loaded in the ViewModel, it doesn't show up if I set IsBusy property before calling the "load" method because it's not asynchronous.</p>
  
  <p>I've tried to set it in a backgroundworker but it crashes when I create the TabItem to add it to the TabItems list (UnauthorizedAccessException).</p>
  
  <p>Any idea??? Thanks in advance.</p>