[XeTeX] accented character ṛ within \section{ṛ}

[TIMOTHY P. LIGHTHISER]

Hi!

I use texlive/2009; TexShop 2.33; and 10.4.11.

I am also now using a font called Junicode (http://junicode.sourceforge.net).

When the accented character ṛ (-r- with an underdot) is input within
\section{}, a box appears in the pdf rather than the character.

At the same time, however, this character does appear within the body
of the text, as well as within the header.

A minimal example is below.

Thanks in advance for any help.


%!TEX TS-program = xelatex
%!TEX encoding = UTF-8 Unicode
\documentclass[a4paper,10pt,draft,twoside]{book}
\usepackage{xltxtra}
\usepackage{lipsum}

\setmainfont[Mapping=tex-text]{Junicode}
\defaultfontfeatures{Mapping=tex-text}

\begin{document}
\tableofcontents

\chapter{Tṛtīyo 'dhyāyaḥ}
Tṛtīyo 'dhyāyaḥ

\lipsum[1-8]

\end{document}