[pstricks] Problem with Seminar

[Hendri Adriaens]

> (/usr/share/texmf/tex/generic/pstricks/pst-lens.tex
> `PST-Lens' v1.0, 2001/02/19 (Denis Girou and Manuel Luque)
> (/usr/share/texmf/tex/generic/pstricks/pst-key.tex
> keyval: 1998/07/23 v1.11 key=value parser (DPC)

You're loading pst-key after loading xkeyval. Update the pstricks
package that still use pst-key, see also http://www.pstrick.de

-Hendri.