[pstricks] Problems with psgraph

[Martin Sievers]

Hello everyone,
I have a problem with the psgraph-environment. The following example
results in a graph which is too wide. Why is that and how can I get an
exactly 12cm graph?

Additionally I'd like to change the labelsizes with the labelFontSize
parameter. When using as an optional parameter for psgraph I always get
four Font warnings (as there are four, I guess the come from the
x-Axis): Command \small invalid in math mode. In the documentation
(chapter 19.1) I can't find an explanation for that, except that there's
just an psaxes command while the psgraph environment is supposed to pass
the options to psaxes, so it shouldn't make a difference.

Thanks in advance for your help.
Martin


\documentclass{minimal}
\usepackage[ngerman]{babel}
\usepackage[latin9]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[prologue,dvipsnames,showerrors]{pstricks}
\usepackage{pst-plot}
\usepackage{pstricks-add}
\listfiles
%
\begin{document}
\begin{pspicture}(0,0)(12,9)
\psgrid
\psset{algebraic,Ox=1,Dx=0.05,Dy=5,xAxisLabelPos={0.785,0},xAxisLabel={$d$},yAxisLabel={$n^*$},subticks=5}
%
\begin{psgraph}(1,0)(0.79,0)(1,40){12cm}{9cm}
\end{psgraph}
\end{pspicture}