New Post: caliburn.micro not showing dialog after application install

hi.

i've got a bit of a problem with caliburn micro 1.4.0 and wpf app developed in visual studio 2010 targetting .net framework 4.0. So here's the rundown of the problem. I've created a visual studio installer project. Added the project output from my app. so far so good. The application installs without a problem. i can run the application without problems, but when i try to close the application a popup dialog should appear. but nothing happens, no dialog, just a black window nothing more.
this also happens throughout the entire application no popups/dialogs whatsoever are showing.

here's the code from my shellviewmodel to show the dialog:

public override void CanClose(Action<bool> callback)
        {
            var modalD = IoC.Get<ModalDialogViewModel>();
            modalD.TituloModal = "Encerrar Aplicação";
            modalD.MensagemModal = "Deseja encerrar a aplicação?";
            modalD.ModalHeight = 250;
            modalD.ModalWidth = 250;
            bool? result = WindowManagerWindow.ShowDialog(modalD);
            if (result == null) return;
            if ((bool) result)
            {
                callback(true);
            }
            else
            {
                callback(false);
            }
        }

help would be appreciated
thanks in advance