using the chronology package with babel french option

using the chronology package with babel french option

I'm trying to use the chronology package and it works fine with the
english option in the babel package but if I use
\usepackage[french]{babel}
It doesn't work anymore. I've found a solution (that I don't understand)
on a french forum. It says I can use
\usepackage[babel=true,kerning=true]{microtype}
It works fine with a simple example like this :
\documentclass[10pt,a4paper]{report}
\usepackage[T1]{fontenc}
\usepackage[francais]{babel}
\usepackage{chronology}
\usepackage[babel=true,kerning=true]{microtype}
\begin{document}
\chapter*{Introduction}
\begin{chronology}[5]{1983}{2010}{10cm}[7cm]
\event{1984}{\color{blue}{one}}
\event[1985]{1986}{\small{two}}
\event{\decimaldate{25}{12}{2001}}{\huge{three}}
\end{chronology}
\end{document}
Yet my text throw an exception :
! pdfTeX error (font expansion): auto expansion is only possible with
scalablefonts.\AtBegShi@Output ...ipout \box \AtBeginShipoutBox\fi \fi
\chapter
on this line :
\chapter{Environnement de travail}
I'm fairly new to Latex and I guess that a encoding problem with the font
but I have no idea about the solution.