This question is really for the matplotlib list. Please try to avoid
cross posting. There is a lot of overlap between the readers of both
lists and you can be pretty sure that most of the mpl and scipy
developers will see it in either place.
What is your numerix setting and what is it's version? You can obtain
this by creating a little script that just does 'import pylab'
and then running it with
python myscript.py --verbose-helpful
and reporting the output.