Thank you for answering.
I know FC3 tends to be heavy, but I chose that or MDK 10 because of the easily available and always up to date multimedia packages for those distro. Compiling and installing JACK, MPlayer, Rosegarden and all that stuf is a real pain for a newbie like me.
Anyway, I checked with the mixer in FC3, and no channel is muted.
I gave also a look to the output of "dmesg" and to be honest I can't find a line referring to sound or audio.
So I suppose the kernel module could non be loaded, even if the hardware detection seems to pick the correct one.
such module should be "snd-intel8x0".
I tried a modprobe snd-intel8x0, I got no error messages, but nothing changed, and my little skills with cgi linux end here.
Should I put a line in one of the configure files in order to make modprobe work? I remember something called "modules.conf" or something like that.