okay so hiding the controls seems fairly straightforward - i came up with the following using the visibility.collapsed approach:

Code:
Private Sub invokeOperation_Completed(ByVal Sender As Object, ByVal E As EventArgs)
        If invokeop.Value = 1 Then
            'navigate to the main page

            Label1.Visibility = System.Windows.Visibility.Collapsed
            Label2.Visibility = System.Windows.Visibility.Collapsed
            tbUserName.Visibility = System.Windows.Visibility.Collapsed
            pbPassword.Visibility = System.Windows.Visibility.Collapsed
            btnLogin.Visibility = System.Windows.Visibility.Collapsed

            Me.MainFrame.Navigate(New Uri("/Views/Dashboard.xaml", UriKind.Relative))

        Else
            MessageBox.Show("Invalid credentials", "Try again", MessageBoxButton.OK)
        End If

End Sub
but still, ideally, a new page of it's own would be better - it also errors out when i hit the back button on the browser as well......