BTW, if I do the pygtk test ( >>>import pygtk >>>
> pygtk.require('2.0')
>>>> import gtk ) once, I get an error message. If I do it again
>>>> without changing anything, I get no error message.
This reimport situation you describe is expected. If you import a
module a second time, python simply ignores it. So if it failed the
first time, it will fail silently the next times. You should exist
python and start over. The problem you are experiencing is definitely
with gtk and not matplotlib.
In these situations, the best thing to do is go into DOS or a command
shell (Start->Run->command ENTER). Write a little script test.py that
contains only
import pygtk
pygtk.require('2.0')
import gtk
Then go into the shell, an cd into the dir containing test.py.
Manually set your PATH, something like (depends on which windows
platform you are on)
c:> set PATH=c:\GTK\bin;C:\GTK\lib;C:\Python23;C:\windows\command
c:> python test.py
I know you've checked your path ad nauseum, but there is still a
decent change is the cause of your problem, 9 times out of 10.
Hey, didn't you solve this once before 
? Is this a new platform
for you? Did you reinstall GTK, if so to where? What does
c:> dir c:\GTK\bin
reveal? I assume you've reread
http://www.async.com.br/faq/pygtk/index.py?req=show&file=faq21.012.htp
100 times.
There is a long thread on the pygtk mailing list where Cousing Stanley
got his gtk corrupted by installing glade, which writes some older
libgtk versions into the windows system dir. Do a file search for
libgtk and make sure nothing shows up outside of your GTK install
tree. Read this thread
http://www.mail-archive.com/pygtk@...85.../msg07324.html, which is
filled with good advice.
Good luck!
JDH