\documentclass[a4paper]{article}

% this was a regression:
\usepackage{german}
\usepackage{pgfplots}

\pgfplotsset{compat=1.6}

\begin{document}

\begin{tikzpicture}
	\begin{axis}
	\addplot3[surf,shader=interp,samples=3] {x*y};	
	\end{axis}
\end{tikzpicture}
\end{document}

