New Comment on "MaskedTextBox"

I am using the MaskedTextBox to bind to a string representation of a TimeSpan (i.e. 00:01:00.0) I am binding to the string via a TwoWay binding on the Value property. I have set IncludeLiterals to true and I've set my Mask to "00:00:00.0". The source seems to be updated when I edit from the MaskedTextBox, but the MaskedTextBox is not being updated when the underlying property is changed. INotifyPropertyChanged has been implemented.