[tex-live] problem in texlive 2007, xelatex and hyperref package

[fishy]

for this simple test file ("Adobe Heiti Std" and "Adobe Song Std" are
fonts come from Adobe Reader 8):
===== begin =====
\documentclass[titlepage, a4paper, 12pt]{article}

\usepackage[section]{placeins}
\usepackage[a4paper]{geometry}
\usepackage{indentfirst}
\usepackage{fontspec}
\usepackage{graphicx}
\usepackage[colorlinks,linkcolor=blue%
        ,a4paper%
        ,hyperindex%
        ,plainpages=false%
        ,CJKbookmarks,bookmarksopen=true%
        ,pdfstartview=FitH%
        ]{hyperref}

\setromanfont[BoldFont=Adobe Heiti Std]{Adobe Song Std}

\XeTeXlinebreaklocale "zh"
\XeTeXlinebreakskip = 0pt plus 1pt

\begin{document}

\url{http://www.foo.com}

\end{document}
===== end =====

and when xelatex it, it says:

===== begin =====
## xdv2pdf: use of uninstalled fonts (specified by filename) such as
##
[/usr/local/texlive/2007/texmf-dist/fonts/opentype/public/lm/lmtypewriter12-regula
r.otf]
## is not supported; try using the xdvipdfmx driver instead.
===== end =====

and the text "http://www.foo.com" shown on the pdf is malformed.

but if I replace "\url{http://www.foo.com}" with
"\href{http://www.foo.com}{http://www.foo.com}", it's OK
-- 
regards,
fishy