Hi,
I am trying to write my thesis using org-mode and followed this thread: http://lists.gnu.org/archive/html/emacs-orgmode/2007-12/msg00034.html.
But instead of putting everything in one file, I was creating one file for each chapter with the assumption that like LaTeX I should be able to combine them in one master file.
I am able to export each chapter individually into PDF. I tried to include them in the master file as this:

#+include "~/Documents/thesis/introduction.org"
#+include "~/Documents/thesis/chapter1.org"
#+include "~/Documents/thesis/chapter2.org"
#+include "~/Documents/thesis/discussion.org"

but when I tried to export the master file, I get error messages on figures that I created using tikz package (topbot is a shape I define using tikz):

----8<------->8-----
Latexmk: Reference `fig:figure1' on page 18 undefined
...
...
! Package pgfkeys Error: I do not know the key '/tikz/topbot' and I am going to
ignore it. Perhaps you misspelled it.

----8<------->8-----

I have the same LaTeX headers in each file. I tried moving it to the top of the master file but that did not help.
Concatenating all the files into one sort-of works but when I replaced biblatex' \printbibliography[heading=none] at the end of each file with \newrefsection[biliographyfile] in the combined file, the reference sections become empty.

Is there a nice way to combine multiple org-files that I am missing?

Thanks,
Subha