There seems to be something wrong with the handling of
\author in amsmath.perl package. The following test
file make l2h 99.1 looping :
-----------------------------------------------------------------
\documentclass[a4paper,11pt,twoside]{book}
\usepackage{amsmath}
\title{This is a tile}
\author{Myself}
\date{\today}
\begin{document}
\maketitle
This is a test.
\end{document}
------------------------------------------------------------------
Removing the handling of \author in amsmath.perl
and the result is ok.
I wonder : should amsmath.perl bother with any
special handling of \author (like : \author ... \endauthor)
because it looks like it is trying to do that.
Fabrice Popineau
