Hi Jason
Your PretendEntity doesn't have OnChanged events or implement INotifyPropertyChanged - Binding sometimes works differently when these are not present. Though I don't think it matters in this particular case, watch out when debugging other binding issues.
I think the problem is that the default binding created using the designer updates the DataSource on Validation but if you change it to DataSourceUpdateMode.OnPropertyChanged, I think you will achieve what you want.
If you create your bindings by hand in a Load event or whatever, it should look something like this:
this.textBox1.DataBindings.Add(new System.Windows.Forms.Binding("Text", this.bindingSource1, "Name", true, System.Windows.Forms.DataSourceUpdateMode.OnPropertyChanged));
If you prefer to use the designer, click on (Advanced) under (DataBindings) and change the DataSourceUpdate mode there.
Make this change for both bindings and it works as expected.
Cheers
Simon
PS I've found that whenever you use OnPropertyChanged, you MUST have the preceeding boolean set to True!