PSTricks and opacity with gradient filling

Question

As a follow-up to the fundamental question Opacity and transparency, I'm wondering if it is possible to use opacity effectively in PSTricks with a gradient filling. The MWE provided by the answer to the post linked above does not work when the filling is switched to a gradient. I'm compiling following the chain latex -> dvips -> ps2pdf.

\documentclass{article}
\usepackage{pstricks,pst-grad} 

\begin{document}

\begin{pspicture}(-2,-2)(2,2)
  \psline[linecolor=blue,linewidth=12pt](-2,-2)(2,2)
  %\psframe[fillstyle=solid,fillcolor=red,opacity=0.5](-1,-1)(1,1)
  \psframe[fillstyle=gradient,gradbegin=red,opacity=0.5](-1,-1)(1,1)
\end{pspicture}

\end{document}

Answer 1

\documentclass{article}
\usepackage{pstricks,pst-slpe} 

\begin{document}

    \begin{pspicture}(-2,-2)(2,2)
    \psline[linecolor=blue,linewidth=12pt](-2,-2)(2,2)
    \psframe[fading,startfading=0.3,endfading=0.8,
       fillstyle=slope,slopebegin=red,slopeangle=90,opacity=0.6](-1,-1)(1,1)
    \end{pspicture}

\end{document}