When to Call ViewModel.LoadData? - silverlight

Question

I have a WP7 Silverlight app that displays a bunch of data using Pivot. When first creating the project, the Visual Studio template calls ViewModel.LoadData in Page_Loaded:
private void MainPage_Loaded(object sender, RoutedEventArgs e)
{
App.ViewModel.LoadData();
}
However on MSDN it says you should use OnNavigatedTo instead of Page_Loaded, because OnNavigatedTo is called only once when a page becomes active, while Page_Loaded is called everytime an item is added to the page's visual tree. The MSDN article is for Silverlight 4 instead of for Silverlight Windows Phone though.
You override the OnNavigatedTo method
to examine the navigation request and
prepare the page for display. For
example, you can load the requested
data and enable or disable visual
elements.
Typically, you use the OnNavigatedTo
method instead of creating an event
handler for the Loaded event. The
OnNavigatedTo method is preferable
because it is only called once for
each time the page becomes active. The
Silverlight framework raises the
Loaded event each time the element is
added to the visual tree, which
potentially can happen more than once
when activating a page. The
OnNavigatedTo method is called for
each request, even when the page is
retrieved from the cache. You should
include in this method code that must
be executed for each request rather
than placing that code in the Page
constructor.
Is there any reason why the Visual Studio Pivot template calls ViewModel.LoadData in Page_Loaded?

Answer 1

I think you're confusing LayoutUpdated and Loaded.
Loaded should only get called once each time the page is displayed.
Loading data specific to a page after that page has been constructed is a simple way of working with data tied to a specific page. My guess is that the default templates use this as it's simple to understand and learn from.
Update
The article in MSDN that you refer to is for Page.Loaded. WP7 does not use Page instead it uses PhoneApplicationpage.
Having worked with WP7 for over a year and created dozens of apps, I've never seen the Loaded event called multiple times in a WP7 app.