how can i get 3 section levels instead of just 2?

["Robert P. J. Day" <rpjday@crashcourse.ca>]

  i've puzzled over the manual and can't seem to find the switch to
give me 3 section levels rather than the 2 i'm getting now.  section
11.1 in the manual reads:

=== start

Headings and sections

The outline structure of the document as described in Document
Structure, forms the basis for defining sections of the exported
document. However, since the outline structure is also used for (for
example) lists of tasks, only the first three outline levels will be
used as headings. Deeper levels will become itemized lists. You can
change the location of this switch globally by setting the variable
org-export-headline-levels, or on a per-file basis with a line


     #+OPTIONS: H:4

=== end

  well, here's the entirety of my .org source file:

=== start
#+LaTeX_CLASS: beamer
#+MACRO: BEAMERMODE presentation
#+MACRO: BEAMERTHEME Antibes

#+MACRO: BEAMERCOLORTHEME lily
#+MACRO: BEAMERSUBJECT RMRF
#+MACRO: BEAMERINSTITUTE Opersys, Inc.
#+TITLE: Linux Device Drivers
#+AUTHOR: Karim Yaghmour, Robert P. J. Day
#+OPTIONS: H:3

* Course structure and presentation
** About the instructors
** Course goals
** Presentation format
** Pre-requisites
** Day-by-day outline
*** Day 1
stuff
*** Day 2
more stuff
*** Day 3
even more stuff
=== end

  yet when i generate the PDF, the "Day 1" and "Day 2" entries show up
as list items, not (level 3) subsubsections.  more confusingly, the
user manual above seems to suggest that three levels is the default in
the first place.  is there something else i need to add to, say, my
.emacs customization?

  i'm sure there's something trivially stupid i've done, but that
section in the manual seems pretty clear that that's the only change i
need to make, so if there's something else that has to be done, it
should be mentioned there as well.

rday

-- 

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Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
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