Confusing error message

[robin]

I have a document on my office machine which will print out normally in
PostScript, but when I do the same at home, I get two error messages
saying:


1. 
extra \endgroup.
\end{flushright}

2.
\begin{document}ended by \end{flushright}

Both systems use Mandrake 8.0 and LyX 1.2.

Does anyone have any idea why this is happening?

Robin