[XeTeX] linguistics trees using qtree: no go

[Cyril]

Hi everybody,
I'm pretty sure that some of you are used to making trees. I'm just  
only trying, and I found a few packages here:
<http://www.essex.ac.uk/linguistics/clmt/latex4ling/trees/>.
I'm just dabbling since yesterday, so I tried my hand at parsetree,  
xyling and qtree. It's with the last one I managed to get exactly the  
trees I wanted, and easily at that.

Thing is, it does not work with XeLaTeX.

%%%
\documentclass[12pt]{article}
\usepackage{geometry}
\geometry{a4paper}
\usepackage{qtree}
\begin{document}

\Tree [.{ai mang\'e} J' [ .pomme une jolie ] ]

\end{document}


%%%

dies with:

This is XeTeX, Version 3.141592-2.2-0.995 (Web2C 7.5.5)
entering extended mode
(./Untitled4.tex
LaTeX2e <2003/12/01>
Babel <v3.8d> and hyphenation patterns for american, french, german,  
ngerman, d
utch, italian, norsk, portuges, spanish, swedish, nohyphenation, loaded.
(/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/geometry/geometry.sty
(/usr/local/teTeX/share/texmf.tetex/tex/latex/graphics/keyval.sty)
(/usr/local/teTeX/share/texmf.local/tex/xelatex/geometry.cfg))
(/Users/cyril/Library/texmf/tex/latex/qtree.sty
Package: 2006/07/10 v.3.1Qtree: tree-drawing for linguistics
(/usr/local/teTeX/share/texmf.tetex/tex/latex/pict2e/pict2e.sty
(/usr/local/teTeX/share/texmf.tetex/tex/latex/pict2e/pict2e.cfg)
(/usr/local/teTeX/share/texmf.tetex/tex/latex/graphics/pdftex.def)
(/usr/local/teTeX/share/texmf.tetex/tex/latex/pict2e/p2e-pdftex.def)
(/usr/local/teTeX/share/texmf.tetex/tex/latex/graphics/trig.sty)))
No file Untitled4.aux.
(/usr/local/teTeX/share/texmf.tetex/tex/context/base/supp-pdf.tex
(/usr/local/teTeX/share/texmf.tetex/tex/context/base/supp-mis.tex
loading : Context Support Macros / Miscellaneous (2004.10.26)
)
loading : Context Support Macros / PDF (2004.03.26)
)
! Undefined control sequence.
\set at color ->\pdfliteral
                          {\current at color }\aftergroup \reset at color
l.7 \Tree [.{ai mang\'e} J'
                             [ .pomme une jolie ] ]
?
Process aborted


Only this
\documentclass[12pt]{article}
\usepackage{qtree}
\begin{document}
\Tree [.{ai mang\'e} J' [ .pomme une jolie ] ]
\end{document}

compiles but there are no lines.

What can I do?
Cyril