thank you Mike.

i have used this code to verify if the hidden property changes.

 void grid_PropertyChanged(object sender, Infragistics.Win.PropertyChangedEventArgs e)
        {
         
            PropChangeInfo propertyChanged = e.ChangeInfo.FindTrigger(null);
            if ((PropertyIds)propertyChanged.PropId == PropertyIds.Hidden)
            {
                //Do something here...

           }
        }