ArgumentException in _grid.Rows.Clear();

Sometimes during refresh operation I get ArgumentException exception with following call stack.

at Divelements.SandGrid.SandGrid.set_FocusedElement(FocusableGridElement value)
at Divelements.SandGrid.InnerGrid.A(GridElement , FocusableGridElement )
at Divelements.SandGrid.InnerGrid.B(GridElement )
at Divelements.SandGrid.GridElement.A(InnerGrid )
at Divelements.SandGrid.GridRow.A(InnerGrid )
at Divelements.SandGrid.GridRowCollection.OnClear()
at System.Collections.CollectionBase.Clear()
at Divelements.SandGrid.GridRowCollection.Clear()

I do nothing special, just plain Rows.Clear() method call.

Some research showed that this exception happens in following situation:

a) There are two SandGrid controls placed in a form.
b) SandGrid control (A) has OnSelectionChanged event assigned.
c) In this event content of SandGrid control (B) is refreshed (Rows.Clear() + Rows.AddRange()).
d) Exception happens when user collapses tree branch that contains selected row.

This is a bug that has now been fixed - thanks.