I'm a new user and I installed matplotlib 0.90.1 on Mac 10.4.9.  I'm using the WxAgg backend, which I installed using MacPorts.  I haven't had a problem so far except when I try to change font properties like family, fontname, and  weight.  For example, the following doesn't work:

figtext(0.8,0.3,"Large Folds", weight='bold', fontname='Helvetica')

I only get the default font (I believe it's Vera) and no bold.  This also happens with the PDF backend so I don't think that's the problem.  I checked the fontManager object and verified that it knows where the fonts are installed on my Mac.  I can call findfont() and it does return the Helvetica font:

In [10]: fm.fontManager.findfont(fm.FontProperties('sans-serif'))
Out[10]: '/System/Library/Fonts/Helvetica.dfont'

Does anyone have a solution for this?