> Unfortunately, the new latex/beamer exporter does not seem to check that
> the user may have wanted to put his/her
> own label on a frame and it adds its own label to the user defined one.
> It is not that difficult to patch org-e-beamer--format-frame to avoid
> adding label when the user provides its own, but is it
> the right thing to do ?

Considering the remark above, I'm don't think that's the best way to
handle the problem. On the other hand, "label" is an option and should
be treated as such (that is, an user should be able to provide its own
value for it). It is implemented now.

Well, thanks for this It solves an easy case that has already asked for in the past.
Now I can do : 

* section
** My frame title                     :B_frame:
:PROPERTIES:
:BEAMER_opt: label=tcs
:BEAMER_env: frame
:END: 

Some text. Some text.  Some text. Some text. 
Some text. Some text.  Some text. Some text. 

* section                                     :B_ignoreheading:
#+BEAMER: \againframe<2>{tcs}

** Following frame
etc.

Not as clean as we might want it, but it is working ok. I had to add an "invisible" section
else the againframe is not exported between frames, but inside the preceding frame.

I don't think it was possible before.
I think it may prove useful to be able to chose the label for the frame.

--
Fabrice