How do I get a busy cursor and disabled window at the same time?

How do I get a busy cursor AND disabled window at the same time? As soon as I disable the main window, the normal cursor reappears. This is happening in Windows XP with wxPython 2.6.1.0.

Here is a small example:

import wx

def OnClick(event):
     wx.BeginBusyCursor()
     wd = wx.WindowDisabler()
     # now the window is disabled, but a normal cursor is displayed :frowning:
     try:
         # simulate a long operation
         for x in range(10):
             wx.Sleep(1)
             wx.Yield()
     finally:
         del wd
         wx.EndBusyCursor()

app = wx.PySimpleApp()
frame = wx.Frame(None, title='Hello World')
BUTTON_ID = wx.NewId()
wx.Button(frame, id=BUTTON_ID, label='Ten Second Test')
frame.Bind(wx.EVT_BUTTON, OnClick, id=BUTTON_ID)
frame.Show()
app.MainLoop()

Regards,
Nate