Bug: table example in the manual doesn't export [8.3beta (release_8.3beta-1216-gb856f6 @ /home/youngfrog/sources/org-mode/lisp/)]

[Nicolas Richard <youngfrog@members.fsf.org>]

In (info "(org) Column groups")

There's an example:
--8<---------------cut here---------------start------------->8---
     | N | N^2 | N^3 | N^4 | sqrt(n) | sqrt[4](N) |
     |---+-----+-----+-----+---------+------------|
     | / |   < |     |   > |       < |          > |
     | 1 |   1 |   1 |   1 |       1 |          1 |
     | 2 |   4 |   8 |  16 |  1.4142 |     1.1892 |
     | 3 |   9 |  27 |  81 |  1.7321 |     1.3161 |
     |---+-----+-----+-----+---------+------------|
     #+TBLFM: $2=$1^2::$3=$1^3::$4=$1^4::$5=sqrt($1)::$6=sqrt(sqrt(($1)))
--8<---------------cut here---------------end--------------->8---

But it won't export (e.g. to html) correctly because [4] is interpreted
as a footnote. Here's a (trimmed down) backtrace :

--8<---------------cut here---------------start------------->8---
Debugger entered--Lisp error: (error "Definition not found for footnote 4")
  signal(error ("Definition not found for footnote 4"))
  error("Definition not found for footnote %s" "4")
  org-export-get-footnote-definition
  (...)
  org-element-map
  (...)
  org-export-collect-footnote-definitions
  org-html-footnote-section
  org-html-inner-template
  org-export-as
  org-export-to-file
  org-html-export-to-html
  org-export-dispatch(nil)
  call-interactively(org-export-dispatch nil nil)
--8<---------------cut here---------------end--------------->8---

Emacs  : GNU Emacs 25.0.50.2 (i686-pc-linux-gnu, X toolkit, Xaw scroll bars)
 of 2015-06-11 on Aurora
Package: Org-mode version 8.3beta (release_8.3beta-1216-gb856f6 @ /home/youngfrog/sources/org-mode/lisp/)