Line break missing when code appears in `frame` in `beamerarticle`

[scmu]

This happens when using lhs2tex with beamer in its article mode. Consider the file below:

\documentclass{article}

\usepackage{beamerarticle}

% Build by lhs2TeX test.lhs | pdflatex --jobname=test

%include lhs2TeX.fmt
%include polycode.fmt

\begin{document}

Code outside frame is displayed normally.
\begin{spec}
f []      = ...
f (x:xs)  = ...
\end{spec}

\begin{frame}
Code in a frame environment missing line break.
\begin{spec}
f []      = ...
f (x:xs)  = ...
\end{spec}
\end{frame}

\end{document}

The file is type set as:

The first piece of code is displayed normally. In the second piece, in a frame environment, the line breaks are missing.

It can be fixed by adding a command \arrayhs after %include polycode.fmt, therefore I think it is related to issue #68.

For testing I am attaching the file here. Typeset it by
lhs2TeX test.lhs | pdflatex --jobname=test.
test.lhs.zip

The lhs2TeX --version is 1.25.