[texhax] \multirow & horizontal centring

[Andre Majorel]

I'm having trouble with this. How do you centre horizontally the
content of a \multirow ? It's "A1" in the example below :

\documentclass[a4paper, 11pt]{report}
\usepackage{array}
\usepackage{multirow}
\begin{document}
\begin{tabular}{|p{4cm}|>{\centering\arraybackslash}m{4cm}|>{\centering\arraybackslash}m{4cm}|}
\hline
\multirow{2}{*}{A1} & \multicolumn{2}{c|}{A2-3} \\
\cline{2-3}
& B2 & B3 \\
\hline
C1 & C2 & C3 \\
\hline
\end{tabular}
\end{document}

Thanks in advance.

-- 
André Majorel http://www.teaser.fr/~amajorel/