I have a feeling this is a bug in wpf. Let me know what you guys think of this.

To keep everything simple I made demo example in .net 4.0

I have a ContentControl with Content bound to Data and ContentTemplate which holds a CheckBox bound to Content.

The problem is Ok property is never true no matter how often I click the CheckBox.

As if CheckBox doesn't pass the new value to ViewModel.

Take a look at this:

```
  <Window.Resources>
    <DataTemplate x:Key="dataTemplate">
      <CheckBox IsChecked="{Binding Path=., Mode=TwoWay}"/>
    </DataTemplate>
  </Window.Resources>

  <Grid>
    <ContentControl Content="{Binding Path=Ok, Mode=TwoWay}" ContentTemplate="{StaticResource dataTemplate}"/>
  </Grid>

```

This is my ViewModel

```
public MainWindow()
{
    InitializeComponent();

    ViewModel vm = new ViewModel();
    this.DataContext = vm;
}

public class ViewModel : INotifyPropertyChanged
{
    private string txt;

    public string Txt
    {
        get { return txt; }
        set { txt = value; this.OnPropertyChanged("Txt"); }
    }

    private bool ok;

    public bool Ok
    {
        get { return ok; }
        set { ok = value; this.OnPropertyChanged("Ok");}
    }

    private void OnPropertyChanged(string propertyName)
    {
        if (this.PropertyChanged != null)
        {
            this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
}

```

Any ideas how to fix this issue with ContentTemplate?