[pstricks] Problem with pst-bspline

[Martin Chicoine]

The following example works:

\documentclass{article}
\usepackage{pst-bspline,pstricks-add}
\begin{document}
\begin{psgraph}[Dx=2,Dy=2,arrows=->](0,0)(-1,-8)(19,6){6cm}{5cm}
  \pnodes{P}(0,0)(2,4)(4,0)(8,-8)(12,0)(14,3)(16,0)(18,-4)
  \psBsplineInterp{P}{7}
  \psBsplineNodes{PB}{7}
  \rput[b](14,3.6){$f$}
\end{psgraph}
\end{document}

However, when I insert the same psgraph in a much larger document (with a
more complicated preamble, but it does not seem to matter), I get the
following error while converting to pdf.  Any idea?

Error: /invalidrestore in --restore--
Operand stack:
   (\340)   6   (nous)   6   (des)   6   --nostringval--   --nostringval--
Execution stack:
   %interp_exit   .runexec2   --nostringval--   --nostringval--
--nostringval--   2   %stopped_push   --nostringval--   --nostringval--
--nostringval--   false   1   %stopped_push   1862   1   3
 %oparray_pop   1861   1   3   %oparray_pop   1845   1   3   %oparray_pop
1739   1   3   %oparray_
pop   --nostringval--   %errorexec_pop   .runexec2   --nostringval--
--nostringval--   --nostringval--   2   %stopped_push   --nostringval--
--nostringval--   1791   7   4   %oparray_pop   --nostringval--   1775   7
4   %oparray_pop   --nostringval--
Dictionary stack:
   --dict:1151/1684(ro)(G)--   --dict:0/20(G)--   --dict:150/200(L)--
--dict:240/300(L)--
Current allocation mode is local
Current file position is 1661683
GPL Ghostscript 8.64: Unrecoverable error, exit code 1
GPL Ghostscript 8.64: ERROR: A pdfmark destination page 41 points beyond the
last page 40.