[Orgmode] problem with org-export-latex-todo-keyword-markup [7.4]

[phaebz]

I defined it as an associative list, as described in the manual:
org-export-latex-todo-keyword-markup evaluates to (("new" . "\\new{%s}") 
("done" . "\\done{%s}") ("todo" . "\\todo{%s}"))

In my LaTeX header are the options:
#+LATEX_HEADER: \def\todo#1{{\color{red}#1}}
#+LATEX_HEADER: \def\done#1{{\color{green}#1}}
#+LATEX_HEADER: \def\new#1{{\color{blue}#1}}

Now I noticed that, in the exported pdf, all todo keywords are typeset in the 
same color, which is always the value of the first element in the a-list. In 
the above example, all keywords get set to blue, i.e. the LaTeX file contains 
odd things like \new{TODO}.

According to the manual, I expect this behaviour - using the value of the first 
element - only for todo keywords for which there is no key in the a-list 
defined.

Am I doing something wrong?