as I was experiencing problems with skype, I've decided to try removing pulseaudio. the internal microphone, in fact, seemed to work properly in audacity when alsa was selected,whereas it kept popping and crackling when using skype.
I removed pulseaudio via terminal, and I immediatly noticed that the volume icon on the top right corner of the screen (the tray) was missing. the Fn keys didn't work as well.
After re-installing pulseaudio the fn keys went back to their normal behaviour, so that I could hear the "pops" when adjusting the volume and see the adjusting horizontal fader "hovering" in the top right corner of the screen. however, the volume icon was still missing.
Honestly, I don't really want to reinstall. It's just a minor issue, and it does not affect usability in any manner whatsoever (since I can access the sound control panel in other ways). It's frustrating, anyway, and I'm really looking forward to solve the issue. I've searched throughout the forums, but I didn't find a solution.
thanks a lot.
post scriptum: does anyone of you have and idea about how to make skype (and only skype) work with alsa? thanks.