Text Formatting ⇒ Parallel package problem

[bdr]

I'm creating a theatrical script with a few of my own environments, but I'm having problems with the vertical placement of Parallel environments. I made a short example that shows the start of the problem:

Code: Select all

\documentclass[12pt,paper=a4]{scrbook}
\usepackage[english]{polyglossia}
\usepackage{blindtext}
\usepackage{parallel}

\newlength{\myindent}
\setlength{\myindent}{\the\parindent}
\setlength{\parindent}{0pt}
\addtolength{\parskip}{\baselineskip}

\newcommand{\speaker}[1]{\ignorespaces\par\hspace{2\myindent}\textsc{#1}\\*}

\newcommand{\Mytext}{%
\speaker{Jan}
\blindtext

\speaker{Arnold}
\vspace{-\baselineskip}
\begin{Parallel}{}{}
\ParallelLText{\blindtext}
\ParallelRText{\itshape \blindtext}
\end{Parallel}

\speaker{Jan}
\blindtext
}

\begin{document}
\Mytext
\Blinddocument
\Mytext
\end{document}

Look at the placement of "Arnold" label at the first and last page. In my real text, the problem is much bigger: after 30 pages, (4 chapters of about 5 sections each) the label is seperated from the parallel environment by a \baselineskip, but labels followed by a plain paragraph overlap with this paragraph. See attachment.

[bdr]

The problem can be solved by switching to the parcolumns package, but parcolumns does not cooperate with lineno.