Another  problem I can't wolve with the new exporter :

I have this text for two columns :

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
*** columns                                                     :B_columns:
:PROPERTIES:
:BEAMER_env: columns
:BEAMER_envargs: T
:END:
[2012-11-17 sam. 17:41]
**** columns                                             :BMCOL:
:PROPERTIES:
:BEAMER_col: 0.5
:END:
some text

**** columns                                                       :BMCOL:
:PROPERTIES:
:BEAMER_col: 0.5
:END:
[2012-11-17 sam. 17:31]
some text
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

I want to export it to beamer with the new exporter; but I can't get the
'T' parameter in the resulting output. It gives me :

\begin{columns}
\begin{column}{0.5\textwidth}
some text
\end{column}
\begin{column}{0.5\textwidth}
some text
\end{column}
\end{columns}

Is my source correct ? I'm not even sure it is intended this way with the
new exporter.

-- 
Fabrice