Hi,
I tried to make my archos recorder 20 speaking.
I unziped the francais.voice in the .rockbox/langs folder and my settings are set to french.
It works with 'spell', 'numbers' but only for filename with 'while hovering' option.
  For testing I done:
- creation a new folder named: steph
- recording a mp3 file that I renamed _steph.talk.
- move it in the folder steph: that doesn't speak!
- move it in the parent folder of steph: that doesn't speak too.
  For filename i had no problem: that work very well.
Thank you for your reply.