Windows Phone 7.1 app keeps crashing

[shism2]

Every time I try to use ReactiveObject in a viewmodel the application will just start crashing. If I use the INotifyPropertyChanged then the application stops crashing.

Here is the code:

using ReactiveUI;
using System.Collections.ObjectModel;
using MyForum.Models;
using System;
namespace MyForum
{
public class MainViewModel : ReactiveObject
{

    public ObservableCollection<PivotInfoItem> _PivotItems { get; set; }
    public MainViewModel()
    {
       this._PivotItems = new ObservableCollection<PivotInfoItem>();
        LoadData();
    }


    public ObservableCollection<PivotInfoItem> PageCollection
    {
        get { return _PivotItems; }
        set
        {
            this.RaiseAndSetIfChanged(x => x.PageCollection,value);
        }
    }



    public bool _loadvis;
    public Boolean OverlayVis
    {
        get
        {
        return _loadvis;
        }

       set
        {

            this.RaiseAndSetIfChanged(x => OverlayVis, value);
        }
    }


    public bool IsDataLoaded
    {
        get;
        private set;
    }

    /// <summary>
    /// Creates and adds a few ItemViewModel objects into the Items collection.
    /// </summary>
    public void LoadData()
    {
        // Sample data; replace with real data
     //   this._PivotItems.Add(new PivotInfoItem() { Title = "Discover" });
     //   this._PivotItems.Add(new PivotInfoItem() {Title="Search" });
        this.IsDataLoaded = true;
    }


}

}

[shism2]

using System;
namespace MyForum.Models
{
public class PivotInfoItem//:INotifyPropertyChanged
{
private String _title;
public string Title
{
get
{
return _title;
}
set
{
//if (_title != value)
//{
_title = value;
// OnPropertyChanged("Title");
//}
}
}

}

}

[shism2]

I got it thanks... I was missing some references.