The error is back:

When one header in a subtree which has the header argument 
:eval never
has the same name as in a following subtree which should be evaluated on
export, the second subtree is not exported. When the name of the header
is changed, the subtree is exported as expected.

--8<---------------cut here---------------start------------->8---
#+PROPERTY: exports both
#+PROPERTY: session *tmp_R*

* Some non-evaluated code
:PROPERTIES:
:eval:      never
:END:
** This is the same header
#+BEGIN_SRC R
cat("\ntwo\n")
#+END_SRC

* Data Assessment Results
** This is the same header
If the name of the header is changed, the subtree is evaluated on export.
#+begin_src R
cat("\nhere it is @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\n")
#+end_src
--8<---------------cut here---------------end--------------->8---
 
Org-mode version 8.2.6 (release_8.2.6-920-gc6d698 @ /Users/rainerkrug/.emacs.d/org-mode/lisp/)
GNU Emacs 24.3.1 (x86_64-apple-darwin13.0.0, Carbon Version 1.6.0 AppKit 1265) of 2014-02-13 on Rainers-MacBook-Pro-2.local

Cheers,

Rainer

-- 
Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology, UCT), Dipl. Phys. (Germany)

Centre of Excellence for Invasion Biology
Stellenbosch University
South Africa

Tel :       +33 - (0)9 53 10 27 44
Cell:       +33 - (0)6 85 62 59 98
Fax :       +33 - (0)9 58 10 27 44

Fax (D):    +49 - (0)3 21 21 25 22 44

email:      Rainer@krugs.de

Skype:      RMkrug

PGP: 0x0F52F982