no sound from firefox

[Uturn]

On my stock debian system, I installed Firefox, as Chromium did not work well.
Now I con't get any sound support form Firefox. However, I do get sound from Rhythmbox.
What could be my problem? (In Manjaro on SDcard Firefox gets sound support, but the system is slow).

[Uturn]

with MrFixit's debian distro, from SDcard I get no sound either, from Chromium this time, on my PBP.

[Uturn]

On my stock debian system, I installed Firefox, as Chromium did not work well.
Now I con't get any sound support form Firefox. However, I do get sound from Rhythmbox.
What could be my problem? (In Manjaro on SDcard Firefox gets sound support, but the system is slow).