Possible Duplicate:
\dot over \vec over : amsmath bug/feature?
Is this a bug (I can't see it reported anywhere)?
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\[
\dot{[\dot{x}]}
\]
\end{document}
produces a misaligned "x" whereas without the \usepackage{amsmath} the alignment is fine.
\dotapplies to[\dot{x}]rather than simply the inner\dot{x}? – Bruno Le Floch Feb 02 '12 at 14:24