this seems to be a potential bug.

Earlier I had bound my field like this.

   <igDP:UnboundField Name="Qty"  Binding="{Binding Quantity, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Label="Quantity" />

As soon as I was updating the Quantity field the property changed event was firing. So far so Good.

Now i needed to add a conditional mask to the Quantity field, so i modified my xaml to.

   <igDP:UnboundField Name="Qty"  Binding="{Binding Quantity, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Label="Quantity" >
                                <igDP:UnboundField.Settings>
                                    <igDP:FieldSettings>
                                        <igDP:FieldSettings.EditorStyle>
                                            <Style TargetType='{x:Type igEditors:XamNumericEditor}'>
                                                <Setter Property="Mask" Value="{Binding Path=DataContext.TradeEditorState.QtyMask, 
                                                    RelativeSource = {RelativeSource FindAncestor, AncestorType={x:Type igDP:XamDataGrid}}}"/>
                                                <Setter Property="Background" Value="Transparent" />
                                            Style>                                         igDP:FieldSettings.EditorStyle>                                     igDP:FieldSettings>                                 igDP:UnboundField.Settings>                             igDP:UnboundField>

This caused the immediate property changed event to break, only when i tab out of the Quantity field does the the property change event get fired.

As i am updating the value the property change event does not get fired as it used to fire before.