org export not working

[John Rakestraw <lists@johnrakestraw.com>]

Hi, list --

Just finished grading exams, writing student comments in org-mode. I've
attempted to export the comments to pdf so that I can print and distribute
to the class, and when I export I get this error message:

--8<---------------cut here---------------start------------->8---
Symbol's function definition is void: org-search-forward-unenclosed
--8<---------------cut here---------------end--------------->8---

C-h f org-search-forward-unenclosed confirms that there's no such function
defined. 

I get the same error message when I export to html and to ascii. It
doesn't seem to matter what I'm trying to export (nor what document class
I use), but here's a dummy sample file that won't export:

--8<---------------cut here---------------start------------->8---
* John Doe
  :PROPERTIES:
  :COLUMNS:  %ITEM %Grade{+}
  :END:
#+BEGIN: columnview :hlines 2 :vlines t :id local
#+END
** Credit for name
   :PROPERTIES:
   :Grade:    6
   :END:
** Terms
   :PROPERTIES:
   :Grade: 16.5
   :END:

** Student 101, Question: 2-1
  :PROPERTIES:
  :Grade: 13.5
  :END:
   - Comments on this student's response to this question on the
     exam. More comments. 
** Student 101, Question: 2-4
  :PROPERTIES:
  :Grade: 16.5
  :END:
   - More comments here. Still more comments.
** Student 101, Question: 3-2
  :PROPERTIES:
  :Grade: 35
  :END:
   - Here we have some numbered comments on the essay. 
     1. This is the first of the numbered comments.
     2. This is the second numbered comment.

--8<---------------cut here---------------end--------------->8---

So far as I know, I've changed nothing in my set-up since last week, when
I successfully exported the exam that I just finished grading. I have,
however, upgraded org in the meantime. 

I realize that this could well be user error, but I can't find what it is.
And my students are going to be pretty unhappy if I don't return these
exams tomorrow. Can someone suggest what I might check?

GNU Emacs 23.2.1
latest git version of org

-- 
John Rakestraw