\renewcommand conflicts with ams?

[James C. Sutherland]

I am trying to alter the format of section headings. I have something like

\renewcommand{\subsection}{ %
  \...@startsection{subsection}{2}{0pt} %
  {1.1ex plus 2.0ex minus 1ex}%
  {1.2ex plus 2.0ex minus 1ex} %
  {\bfseries} %
}

A simple recipe to reproduce:

1. add the above "renewcommand" to the document LaTeX preamble.
2. create a subsection and subsection* environment
3. In document settings -> math options, disable AMS.

This compiles fine.

However, if I the AMS math package gets included by LyX, then any subsection* constructs break. Is this a known conflict with AMS? Now replace step 3 above by enabling AMS. Now the subsection* environments are broken. I have attached a simple LyX file that can serve as a basis for testing. It is currently configured to break.

newfile2.lyx
Description: Binary data