Continuing Font Problems: Some XFT fonts not using XFT engine?

[Taylor Venable <taylor@metasyntax.net>]

Continuing with the font weirdness I've been seeing:

I can set XFT fonts like "DejaVu Sans Mono" for the 'default' face and
it looks great.  However, when I set 'variable-pitch' to use "DejaVu
Sans" or "DejaVu Serif" the XFT engine is not used.  To summarise:

    (set-face-attribute 'variable-pitch nil :font "DejaVu Sans")
       >> hover over something to get a tooltip, see that it's all
          blocky and not anti-aliased

What's weird is that sometimes after trying to use different fonts for
the variable-pitch face, it will start using anti-aliasing again and
then everything works.  I cannot reproduce when this occurs, and it
doesn't seem correlated with the font choice.

My Emacs version is: GNU Emacs 23.0.92.1 (i386-unknown-openbsd4.5,
GTK+ Version 2.14.7) of 2009-04-13 on lionel.metasyntax.net

Fontconfig version is 2.4.2 with XFT 2.1.12 (version numbers taken
from pkg-config output).

-- 
Taylor Christopher Venable
http://real.metasyntax.net:2357/

foldr = lambda f, i, l: (len(l) == 1 and [f(l[0], i)] or
                         [f(l[0], foldr(f, i, l[1:]))])[0]