Install wxPython on Cygwin failed

I performed the steps as shown in
http://gnuradio.org/trac/wiki/wxPythonCygwin to install wxPython in
Cygwin, but something must be wrong.
wxWidget works as the minimal example runs well.
However, wxPython does not seem to work. When I run ‘python demo.py’,
nothing happens.
Then I enter the python interactive mode, and type ‘import wx’, the
python interactive environment terminated and returned to the bash
shell without any messages.
I am sure I applied both patches mentioned in that page.
No idea what is going wrong.
Where should I go now?
thanks