pgf-pie and babel incompatibility?

Question

I'm having a rather strange problem with pgf-pie: it seems not to work very well when using the babel package...

See for yourself:

Without babel

With babel

Here is the code:

\documentclass[a4paper,11pt,final]{scrreprt}
\usepackage{pgf-pie}
\usepackage[french]{babel}

\begin{document}

\centering

\begin{tikzpicture}
\pie{10/A, 20/B, 30/C, 40/D}
\end{tikzpicture}
%
\hspace{1cm}
%
\begin{tikzpicture}
\pie[polar]{10/A, 20/B, 30/C, 40/D}
\end{tikzpicture}

\vspace{2cm}

\begin{tikzpicture}
\pie[square]{40/A, 30/B, 20/C, 10/D}
\end{tikzpicture}
%
\hspace{1cm}
%
\begin{tikzpicture}
\pie[cloud, text=inside, scale font]{10/A, 20/B, 30/C, 40/D}
\end{tikzpicture}

\end{document}

Has anyone seen this before? How to fix it?

Thanks in advance.