Data biding from checkbox for displaying and hiding tooltip doesn't get updated

WPF Code

<Button Name="btnCancel" Content="Cancel" 
                        ToolTipService.IsEnabled="{Binding GeneralDisplayTooltipsForPreferencesAndSearchOptions, UpdateSourceTrigger=PropertyChanged}"
                        ToolTip="Discard Changes On All Tabs and Close Dialog"
                    Height="25" Width="80" Margin="0,5,2,5" VerticalAlignment="Center" Click="btnCancel_Click

-------------------------------------------------------
C#

public class General : INotifyPropertyChanged, IPreferencesGeneral
    {
        private bool generalDisplayTooltipsForPreferencesAndSearchOptions = false;
        [field: NonSerializedAttribute()]
        public event PropertyChangedEventHandler PropertyChanged = delegate
        {

        };

 public bool GeneralDisplayTooltipsForPreferencesAndSearchOptions
        { 
            get { return generalDisplayTooltipsForPreferencesAndSearchOptions; }
            set
            {
                if (!Equals(generalDisplayTooltipsForPreferencesAndSearchOptions, value))
                {
                    generalDisplayTooltipsForPreferencesAndSearchOptions = value;
                    OnPropertyChanged("GeneralDisplayTooltipsForPreferencesAndSearchOptions");
                }
            }
        }
}

Hi, I need to display some tooltips and have a checkbox to display it and hide it. I have the databiding but it won't get updated. The bool value seems always true which means that the tooltip won't disappear even when the checkbox is unchecked. Thanks. Jean