This issue still exists (I am using Q3 2012 SP1). The EventArgs members "OldItems" and "NewItems" sometimes do not have correct values.
What I wanted to achieve is to get a BindingSource updated when an user changes the sorting of a RadGridView on the same Form. Call it kind of "sorting synchronisation" (Direction and Property/ColumnName) between the two of them. This is what I use until the error is fixed... if so.