Please provide a link to your config.log file so that we can check it.

You can find it here:

http://www.hildebrand.tv/php/config.log

Are you sure you have only one (1) sablotron version installed in your system? What does "/usr/bin/sablot-config --version" output ?

Does this work:

# rm config.cache
# ./configure --disable-all --with-xslt-sablot --enable-xslt

I already added that output in my initial post. And I am sure that I have one install of sablotron on my machine. I even tried to install php on another machine (also GentooLinux) and I had the same problem there. 

Installing Sablotron 1.0.1 gives the same problem. 

> Does this work:
> # rm config.cache
> # ./configure --disable-all --with-xslt-sablot --enable-xslt

....
checking whether to enable xslt support... yes
checking for XSLT Sablotron backend... yes
checking for libexpat dir for Sablotron XSL support... no
checking for iconv dir for Sablotron XSL support... no
checking for JavaScript for Sablotron XSL support... no
checking for Sablotron libraries in the default path... found in /usr
checking for sablot-config... found
checking for Sablotron version... >= 0.96
checking for iconv... yes
checking for SablotSetEncoding in -lsablot... yes
checking for SablotGetOptions in -lsablot... yes
....

That seems to work. Strange that it doesn't work if I set the directory where it should find it.

Something strange is happening here.

If I do the original configure statement but without the option "--with-jpeg-dir=/usr" it works perfectly. If I add the option  again it gives me the sablot version error.

Exactly HOW do you install sablotron?

I used gentoos packagemanager "emerge" to install Sablotron.

Somehow I have the idea it isn't really a sablotron issue. Maybe it has something to do with the combination of configure parameters. Replacing certain parameters which have nothing to do with Sabloton can result in the Sablot-version-error.

I will do a manual install of sablotron to check if the gentoo packagemanager has done something strange.

I've just done a manual install of sablotron. Did the configure again but then with the option --with-xslt-sablot=/opt/sablot and still I get the same error. So it has nothing to do with Gentoo.

What is the shortest possible configure line with which you can reproduce this?

This configure is a lot smaller and throws the error:

./configure  \
--with-apache=../apache_1.3.33 \
--with-gd=/opt/libgd2 \
--with-xslt-sablot=/usr \
--enable-xslt \
--with-jpeg-dir=/usr \
--with-java=/opt/j2sdk1.4.2

My problem was in missing libjvm.so. I use blackdown-jre on my Gentoo and I have setup for LDPATH only for /opt/blackdown-jdk-1.4.2.01/jre/lib/i386/{,native_threads,classic}.  But the libjvm.so is in /opt/blackdown-jdk-1.4.2.01/jre/lib/i386/{client,server} directories. And while configuring php-cgi, it links with some library, which requires libjvm.so. And I had a problem that there was neither lib/i386/client nor lib/i386/server in /etc/ld.so.conf. I have updated my system, now I have these paths in ld.so.conf and configure script works.
Problem was while compilation C program to get version of Sabltron (see end of config.log). Try to copy this C program to some file, delete #include "conftest.h" and try to compile using the last gcc command in config.log and than try to run the result of compilation. It should say what library it is missing. I hope it will help.

My problem has nothing to do with Java. I can make a configure statement without the option "--with-java=/opt/j2sdk1.4.2" and still get the sablotron error. It is just one part of the few combinations which make the error occur.

Why don't you try my previous configure statement and tell me what results you get?

Reading comprehension:

"Problem was while compilation C program to get version of 
Sabltron (see end of config.log). Try to copy this C program 
to some file, delete #include "conftest.h" and try to compile 
using the last gcc command in config.log and than try to run 
the result of compilation. It should say what library it is 
missing. I hope it will help."

And FYI: All your configure lines (with fixed paths) work fine on my system(s). Your /etc/ld.so.conf file is propably missing some paths. This still isn't PHP bug.