Cross thread exception... where 's my problem?

   Hello,
I'm relatively new to DevForce IdeaBlade / Application Framework...
as far I've done some testing everything was ok... I load a single view, done my stuff, close and reopened project and everything was ok... now that I've started opening a new page things get damaged...

I've got a screen defined as 

    [Export]
    public class SecuritiesNoteManagerViewModel : Screen
    {
 private BindableCollection<SecuritiesNoteResult> _SecuritiesNoteResult = new BindableCollection<SecuritiesNoteResult>();
        private readonly IApplicationRepository _repository;
        private readonly IWindowManager _windowManager;

        private DateTime _date;
        private int _ancheEstinti;

        [ImportingConstructor]
        public SecuritiesNoteManagerViewModel(IApplicationRepository repository, IWindowManager windowManager)
        {
            _repository = repository;
            _windowManager = windowManager;
        }
...

   public void OpenSecuritiesNote()
        {
            _windowManager.ShowWindow(new ReportViewModel(_repository)); //here troubles start
        }

}

When I click the Button and the OpenSecuritiesNote starts I got an execption inside my Telerik Reporting saying :

An EntityManager can only execute on a single thread. This EntityManager is authorized to execute on the thread with id=’8’; the requested operation came from the thread with Id=‘12’.

Consider calling the EntityManager’s asynchronous methods; they work safely on background threads managed by DevForce. 

You may have to disable this cross-thread checking for specific reasons such as automated testing. Please review our documentation on multi-threading issues and the EntityManager.AuthorizedThreadId property.

The method that raises the exception is :

  public DomainObject GetSecuritiesNoteForReport(int xxx, DateTime data)
        {
            var query = Manager.DomainObject .Where(nota => nota.xxx == xxx&& nota.DATA == data);

            var op = query.Execute(); //here

            if (op.ToQuery().Count() == 0) return null;

            var item = op.ToQuery().FirstOrNullEntity();

            return item;

        }

I use IoC pattern just not to create a new manager... I think that the reportviewer of telerik creates the report on another thread (probably it's so since I use the domain model on a server, not in the WPF client)

Thanks