Adding pictures to a listview...

I am generating a listview dynamically from CSV files, and want to add images next to them...

I have added a ImageIndex and added images to it's array going up to 4

Now my code looks like this:

VB Code:

' build the navigation tree
                Dim sectionNode As TreeNode
                treeViewNavigation.BeginUpdate()
                Dim section As GenericTree.TreeElement
                For Each section In gt.Root.children
                    sectionNode = New TreeNode(CType(section.reference, SectionElement).Name)
                    treeViewNavigation.Nodes.Add(sectionNode)
                    treeViewNavigation.ImageIndex = 1
                    Dim subsection As GenericTree.TreeElement
                    For Each subsection In section.children
                        sectionNode.Nodes.Add(New TreeNode(CType(subsection.reference, SubsectionElement).Name))
                        sectionNode.ImageIndex = 2
                    Next subsection
                Next section
                treeViewNavigation.EndUpdate()
                treeViewNavigation.ExpandAll()

ANy ideas why it doesn't display the images? Is there an extra setting I am supposed to do?

Thanks.