[tex-live] kpsewhich search order and how to change it

[Philip K.F. Hölzenspies]

Dear all,

I'm truly sorry if I could have easily found the answer to this problem in the 
archives or on a wiki. If so, I must have overlooked.

My problem is rather far beyond my understanding of TeXLive and especially 
Kpathsea. It seems I can't get TeX to use the texmf in my home directory. 
Although, sometimes it does. I can't illustrate my confusion better than by 
the following.

I use a package called TikZ/pgf. When running my LaTeX document, some files 
come from my texmf and some from the system's global texmf (in /usr/share/). 
Since the version in my personal texmf is newer, this creates problems. See 
this test:

holzensp:~> kpsewhere tikz.sty pgfcore.code.tex
/home/aid/holzensp/texmf/tex/pgf/latex/pgf/frontendlayer/tikz.sty
/usr/share/texmf/tex/latex/pgf/frontendlayer/tikz.sty
/home/aid/holzensp/texmf/tex/pgf/generic/pgf/basiclayer/pgfcore.code.tex
/usr/share/texmf/tex/generic/pgf/basiclayer/pgfcore.code.tex

So, both files are in both my and the global texmf. Note that in both cases, 
kpsewhere shows the /home/aid/holzensp/texmf first. However, when I as 
kpsewhich:

holzensp:~> kpsewhich tikz.sty pgfcore.code.tex
/home/aid/holzensp/texmf/tex/pgf/latex/pgf/frontendlayer/tikz.sty
/usr/share/texmf/tex/generic/pgf/basiclayer/pgfcore.code.tex


Can anyone explain this? Is there a way to force the use of files in my own 
texmf?

Regards,
Philip

PS.
For debug info: I use the default TeX Live 2007 distribution as packaged for 
openSuSE 10.3. This means I have kpathsea version 3.5.6