[pstricks] pst-func -- \pst at linetype undefined

[D. P. Story]

Just downloaded pst-func package by Herbert Voss. I extracted on of 
the examples from pst-func-doc.tex and tried to run it, but keep 
getting

! Undefined control sequence.
\psls at dashed ...ashadjust \psk at dash \pst at linetype 
                                                  \space \tx at DashLine 
\else ...

test.tex(14) : ...le=dashed,Abbreviation=1]{-2}{4}

My test file is

\documentclass{article}
usepackage{pst-func}

\begin{document}
\begin{pspicture*}(-3,-5)(3,10)
\psaxes[Dy=2]{->}(0,0)(-3,-5)(3,10)
\psset{linewidth=1.5pt}
psPolynomial[coeff=-2 1 -1 .5 .1 .025 .2,linecolor=red,linestyle=dashed,Abbreviation=1]{-2}{4}
\end{pspicture*}
\end{document}

Can someone explain why I am getting this message? Do I need to 
update one of the basic pstricks files?

dps