[XeTeX] Conflicts between AMS document classes and polyglossia

[Rémy Oudompheng]

Hi,

I am experiencing problems compiling documents using AMS document
classes (such as amsart), using a standard setup of TeXLive (TeXLive
2008 packages from ArchLinux).

For example, the following file :

\documentclass{amsart}
\usepackage[english]{polyglossia}
\begin{document}
\title{Title}
\author{Author}
\maketitle
Several words.
\newpage
More words.
\end{document}

fails with the following error :

! Use of \protect doesn't match its definition.
<argument> ...orespaces }\protect \MakeUppercase  
                                                  {Author}
l.11 \end{document}
                   
? 

Removing the option for the polyglossia package seems to remove the
error. How can I work around this problem ?

Regards,
  Rémy Oudompheng.