Up to now, the behavior of \rput and node seem to be mysterious.
The following code tells us what I mean.
\documentclass[pstricks,border=12pt]{standalone}
\usepackage{pst-node}
\psset{saveNodeCoors}

\begin{document}
\begin{pspicture}[showgrid=bottom](6,6)
\pnode(1,1){A}
\rput(4,0){\psline(0,0)(A)}
\end{pspicture}

\begin{pspicture}[showgrid=bottom](6,6)
\rput(4,0){\pnode(1,1){A}\psline(0,0)(A)}
\end{pspicture}

\end{document}