\listfiles \documentclass{article} \usepackage{siunitx} \sisetup{debug} \begin{document} This is the bug test-case document for the \textsf{siunitx} package.\\ Please put your demonstration here, and e-mail to the package author. \begin{center} \texttt{joseph.wright@morningstar2.co.uk} \end{center} \end{document}