is it bug of VS.net (TaskPane)??

I'm use Xtreme Suite ActiveX 9.51 in windows 2000 using vb.net.
I created a user control, in which there is a listview. but it does not work when using the following codes.

             dim group ...  
             dim item ...
             Dim a As New UserControl1
             Group = wndTaskPanel.Groups.Add(0, "aaa")
             Item = Group.Items.Add(0, "", XTPTaskPanelItemType.xtpTaskItemTypeControl, -1)
             Item.Control = a
             a.Dock = DockStyle.Fill

but when click the Group, the appearance can be seen but disappeared immediately.

Please kindly advise it's due to my fault or just the bug of VS.net. Appreciate your prompt reply. tks & b.rgds

many thanks for your kind response. but regret that same result got as previous without

it works!!

   thanks