Thanks for the answers about the misbehaving of the board with Firefox. I use what is, I think, the most recent version (14.0.1) and, to be honest, I would like to avoid installing any more stuff on my system, especially from Google. And the forum FAQ is unavailable (HTTP 500 - Internal server error). FWIW, the Cake board is the only one giving me this problem, i.e. Gearslutz, KVR or Steinberg ones work exactly as expected. But back to the topic and sorry again...
EDIT : solved ! Just have to use the HTTP 'br' markup each time I want a CR to appear. Still think it isn't normal, though...