I have two level treeview with grid look.  When clicking on the parent row it needs to expand and make sure children nodes are in the view of the screen.

This works fine until user scrolls away and first element is not visible anymore. At that point if user tries to clicking on different parent node he get an error (screenshot attached): 

"Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index"

Usually the error happens if child item of ParentA node active/seletected, and User Clicks on ParentB node.  As soon as the Expanded or BringIntoView triggers, It errors out

I tried to refresh treeView, and put delay.  Seemed to work at first but now I see it still happening. We're using version 12.1. Please help.  The source code below

           Dim prevNode As UltraTreeNode = Nothing

            ....

           Private Sub tvOrders_AfterSelect(ByVal sender As System.Object, ByVal e As Infragistics.Win.UltraWinTree.SelectEventArgs) Handles tvOrders.AfterSelect

           .....

            If e.NewSelections.Count > 0 Then
                If TypeOf e.NewSelections(0).Tag Is SCE.SCEInterfaces.IOrder Then
                    tvOrders.Refresh()
                    Application.DoEvents()
                    If prevNode IsNot Nothing AndAlso prevNode IsNot e.NewSelections(0) Then
                        prevNode.Expanded = False
                    End If

                    e.NewSelections(0).Expanded = True
                    If e.NewSelections(0).Nodes.Count > 0 Then
                        e.NewSelections(0).Nodes(0).BringIntoView(True)
                    Else
                        e.NewSelections(0).BringIntoView(True)
                    End If

                    _ActiveOrder = DirectCast(e.NewSelections(0).Tag, SCE.SCEInterfaces.IOrder)
                    _selectedItem = Nothing
                    prevNode = e.NewSelections(0)
                Else
                    _ActiveOrder = DirectCast(e.NewSelections(0).Parent.Tag, SCE.SCEInterfaces.IOrder)
                    _selectedItem = DirectCast(e.NewSelections(0).Tag, SCE.SCEInterfaces.IOrderItem)
                    prevNode = e.NewSelections(0).Parent
                End If

            End If

            ....

            End Sub