When I write
\begin{lstlisting}
/opt/httpServer/lighttpd/config/lighttpd.conf
\end{lstlisting}
and view the line in my PDF document, copy and paste it to an editor, I receive
/ opt / h t t p S e r v e r / l i g h t t p d / c o n f i g / l i g h t t p d . c o n f
Does anyone know the reason for this and maybe even a solution?