[OS X TeX] PB with kerkis

[Eric DÉTREZ]

Hello

I'm using kerkis.sty to print wih bookman fonts but il seems to have a  
problem with math.
Here is a minimal sample :
***************************************
\documentclass{article}
\usepackage{kmath,kerkis}

\begin{document}

\begin{enumerate}
\item $$A_2 \over B_3$$

\item $$A_2 \over B_3$$

\item $$A_2 \over B_3$$

\item $$A_2 \over B_3$$

\item $$A_2 \over B_3$$

\item $$A_2 \over B_3$$

\item $$A_2 \over B_3$$

\end{enumerate}

\end{document}
***************************************
The compilation is fine (with pdflatex) but when I print I get only 5  
items and an error :
***************************************
ERROR: stackoverflow
OFFENDING COMMAND: --nostringval--

STACK:
***************************************

printed on the page

I use Mac osx 10.5.2 with a HP Laserjet 1320.

Any idea ?