DISPLAY variable-error on a remote machine

[Joachim Ziegler <ziegler@mpi-sb.mpg.de>]

Hello list,

I'm using the XSLT stylesheets 1.62.4. When I'm directly logged in on my 
machine, everything works fine.

But using it as a remote machine, being logged in via ssh,
I get the following error message:


[...]
Writing html/ch01s03.html for sect1(sec.CompilingLinkingRunning)
Writing html/ch01.html for chapter(cha.InstallingAndRunning)
Writing html/ch02s01s01.html for sect2
Writing html/ch02s01s02.html for sect2
Writing html/ch02s01.html for sect1(sec.Strings)
Error at xsl:value-of on line 238 of 
file:/KM/usr/ziegler/DocBook/docbook-xsl-1.62.4/html/graphics.xsl:
   Exception in extension function java.lang.InternalError: Can't 
connect to X11 window server using ':0.0' as the value of the DISPLAY 
variable.
Transformation failed: Run-time errors were reported


What have the stylsheets to do with the X11 server, and how can I use 
them from a remote connection?

Any help appreciated!

Greetings,
Joachim