[XeTeX] New fontspec problem...

[Stephen Moye]

I just tried to typeset fontspec-example.tex and got this:

This is XeTeX, Version 3.141592-2.2-0.99b (Web2C 7.5.3)
entering extended mode
(./fontspec-example.tex
LaTeX2e <2003/12/01>
Babel <v3.8d> and hyphenation patterns for american, british, french,  
german, n
german, dutch, italian, norsk, portuges, spanish, swedish,  
nohyphenation, loade
d.
(/usr/local/teTeX/share/texmf.tetex/tex/latex/base/article.cls
Document Class: article 2004/02/16 v1.4f Standard LaTeX document class
(/usr/local/teTeX/share/texmf.tetex/tex/latex/base/size12.clo))
(/usr/local/teTeX/share/texmf.tetex/tex/latex/euler/euler.sty
Package: `euler' v2.5 <1995/03/05> (FJ and FMi)

L! Illegal unit of measure (pt inserted).
<to be read again>
                    M
l.9 \setromanfont{Hoefler Text}

?

What have I missed? According to the i-Installer, my TeX setup is up- 
to-date...

Thanks for any enlightenment!

SGM