Bind Pivot SelectedIndex causes app random crash in WP 8.1 universal app [MVVM Light]

Question

I have an universal app for WP 8.1 with a page and a Pivot in it. The "SelectedIndex" property of the pivot is bind to a property in the VM like this (code in MainViewModel.cs):
public object SelectedPivotIndex
get { return this.selectedPivotIndex; }
set
if (this.selectedPivotIndex == value) return;
this.selectedPivotIndex = value;
RaisePropertyChanged(() => SelectedPivotIndex);
Page code:
<Pivot x:Name="ContentPivot"
x:Uid="ContentPivot"
SelectedIndex="{Binding SelectedPivotIndex, Mode=TwoWay}"
>...</Pivot>
The problem is from time to time i'm having app crash (in App.xaml.cs): "Unhandled exception" with type "COMEXCEPTION". This crash stop if I remove the bind of the "SelectedIndex" in the xaml, but I cannot understand
why it ocurs. Sometimes even the debugger is not shown and the app closes without any error information. BTW I'm using MVVM Light, so the "glue" between the view (page) and the VM is set in the page:
<Page
DataContext="{Binding Source={StaticResource Locator}, Path=Main}"
>
EDIT:
I'm able to reproduce the crash with this behavior: Open app, navigate to another page, come back to the pivot page (several times) and flip throught the pivotitems.

Answer 1

I've solved the problem with a workaround. In page code behind:
private void ContentPivot_SelectionChanged(object sender, SelectionChangedEventArgs e)
var vm = this.DataContext as IPivotable;
if (vm != null)
vm.OnPivotItemChange(this.ContentPivot.SelectedIndex);
The interface:
public interface IPivotable
void OnPivotItemChange(int pivotIndex);
And finally the VM:
public void OnPivotItemChange(int pivotIndex)
try
if (pivotIndex == 0)
// Do stuff here...
catch (Exception e)
That's all, thanks for the... help?