[Orgmode] beamer export

[Antony Ware]

I've been having a problem exporting to beamer. I've now found the problem and 
fixed it, but it was (to my mind) something pretty obscure, and I think it 
might be of interest to the list, at least as a salutary tale. 

When I opened an org file such as the example beamer presentation from the 
manual (section 12.6.6) and executed C-c C-e d, it kept generating a .tex file 
with an article document class, instead of the expected beamer class.

After a few days of frustrated searching through the manual and tutorials, and 
this list, for any clues, I found some advice to run something like 

/usr/bin/emacs -Q -l test.el

with a series of versions of test.el progressively approximating my .emacs 
file. I was expecting the problem to lie in one of my org- or latex-specific 
settings, but eventually found the cause of the problem to be that the variable

case-fold-search

was being set to nil (its default value) as one of my custom-set-variables. I 
don't remember why. Anyway, according to the information from C-h v, this makes 
the setting buffer-local, and for some reason that fouled up the beamer export. 
When I commented out that line, everything worked as advertised.

I'd be interested to hear from anyone who could shed light on why that might be.

Cheers,

Tony
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I am running Emacs 23.1.96 (9.0), and org-mode 7.01g. I'm using MacTeX 2009.