[wxPython] wxListCtrl & Images

I am trying to use the wxLC_ICON style with the wxListCtrl, but the icons
never display. Below is a test code snippet. Anyone see what I am doing
wrong?

from wxPython.wx import *

class CTest( wxFrame ):
   def __init__(self):
      wxFrame.__init__(self, NULL, -1, "test" )
      il = wxImageList(16, 16)
      idx1 = il.Add( wxBitmap('inboxs.bmp', wxBITMAP_TYPE_BMP) )
      list = wxListCtrl(self, -1, style = wxLC_ICON )
      list.SetImageList(il, wxIMAGE_LIST_NORMAL)
      list.InsertImageStringItem(0, "test label", idx1)

class CApp( wxApp ):
   def OnInit(self):
      frame = CTest()
      frame.Show(true)
      self.SetTopWindow(frame)
      return true

app = CApp(0)
app.MainLoop()