[TxMt] LaTeX Syntax coloring problem

The minimal test case below shows that something in the parsing of the newenvironment command is throwing off the syntax coloring by the LaTeX bundle, at least on my system (TM 1.5.7 1464 on Leopard). The text in the document is incorrectly parsed as being in a math environment.

\documentclass{article}

\usepackage{amsmath}

\newenvironment{choice} {\left\lbrace\begin{gathered}} {\end{gathered}\right\rbrace}

\begin{document}

Text incorrectly parsed as being in a math environment.

\end{document}

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Any ideas of how to fix the parsing?

-- Kai von Fintel fintel@gmail.com