Tkinter, since tk 8.5 apparently, does not find all the fonts that tk knows about.

I'm using Python 2.6.5 on Linux but have seen this on previous versions.  I have added the font with "xset fp+ <some font directory>"".  The font is Richard Jones' zed font, available from http://www.cs.kent.ac.uk/people/staff/rej/Zedfont/latest/

xlsfonts shows the font.

tk sees the font; in wish if I type "font families" there it is:

% font families
{fangsong ti} fixed {clearlyu alternate glyphs} charter lucidatypewriter zedfont {latin modern roman}  ...

In Tkinter I do not see the font:
>>> from Tkinter import *
>>> r = Tk()
>>> import tkFont
>>> tkFont.families(r)
... no sign of the zedfont here.

Is this expected behaviour?  Is there another way to install the font that avoids this problem?