i have been using 2 level grids for a little while now.  (a parent row and child row).  when you expand the parent row i would like the Child set to open.  we have been using some thing like this

Private Sub dgAccounts_RowExpansionChanged(ByVal sender As Object, _
                                               ByVal e As RowExpansionChangedEventArgs) _
                                               Handles dgAccounts.RowExpansionChanged
       If e.Row.RowType = Infragistics.Silverlight.RowType.DataRow Then

            Dim rw As Row = e.Row

            For Each childLayout As ChildBand In rw.ChildBands

                childLayout.IsExpanded = True
               
            Next

        End If

    End Sub

When we try to use this same set up with a 3 level grid the page freezes at random and then we get an Exception caught by the App.xaml.vb page.  here is the message:

"Exception from HRESULT: 0x88000FA8"

we also have a button on these pages that calls this:

Private Sub ExpandRows(ByVal rows As RowCollection)

        For Each r As Row In rows

            r.IsExpanded = True

            If r.HasChildren Then

                ExpandRows(r.ChildBands(0).Rows)
            End If
        Next
    End Sub

Is there any way we shouldnt be able to use this set up with another level in the grid?

what would be the recommended way to do this?

thanks