How do I copy objects inside one thumbnail viewer to another?

    Private Sub AddFileToFilesList(ByVal filename As String)
        Dim filePidls(0) As Aurigma.GraphicsMill.WinControls.Pidl
        filePidls(0) = Aurigma.GraphicsMill.WinControls.Pidl.Create(filename)

        Dim listItems As Aurigma.GraphicsMill.WinControls.ThumbnailListItem() = Aurigma.GraphicsMill.WinControls.ThumbnailListItem.Create(filePidls)
        ThumbnailListView1.Items.Add(listItems)
    End Sub

    Private Sub AddFileToQueue(ByVal Listitem As ThumbnailListItem)
        ThumbnailListView2.Items.Add(Listitem)
    End Sub

    Private Sub UFlatButton7_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles UFlatButton7.Click
        If Not ThumbnailListView1.SelectedItems Is Nothing Then
            For Each item As ThumbnailListItem In ThumbnailListView1.SelectedItems
                ThumbnailListView2.Items.Add(item.Clone)
            Next
        End If
    End Sub

System.InvalidOperationException was unhandled
  Message="Cross-thread operation not valid: Control 'ThumbnailListView2' accessed from a thread other than the thread it was created on."
  Source="System.Windows.Forms"
  StackTrace:
       at System.Windows.Forms.Control.get_Handle()
       at Aurigma.GraphicsMill.WinControls.VirtualListView.GetItemRect(Int32 itemIndex)
       at Aurigma.GraphicsMill.WinControls.VirtualListView.UpdateColumnWidth(Int32 itemIndex)
       at Aurigma.GraphicsMill.WinControls.VirtualListView.TextChanged(Object sender, TextChangedEventArgs args)
       at Aurigma.GraphicsMill.WinControls.ListItemCollection.FireTextChanged(IListItem item, Int32 textInfoId)
       at Aurigma.GraphicsMill.WinControls.ListItemCollection.TextChangedInternal(Object sender, TextChangedEventArgs e)
       at Aurigma.GraphicsMill.WinControls.ListItem.FireTextChanged(Int32 textInfoId)
       at Aurigma.GraphicsMill.WinControls.ThumbnailListItem.FireEvalMethod0Events()
       at Aurigma.GraphicsMill.WinControls.ThumbnailListItem.EvaluateMethod(Int32 methodIndex)
       at Aurigma.GraphicsMill.WinControls.Queue.EvaluateQueue()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.runTryCode(Object userData)
       at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()