My internal microphone is not working in Skype. The first thing I did was checking if the microphone was found by pulseaudio. I opened up pavucontrol and recognized that the microphone was there but the sound level bar does not move when speaking into the microphone. The microphone is not muted. I also checked this in alsamixer. The sound level bar moves for the monitor device when playing music.
BUT: pacat -r > test, arecord -vv -fdat test.wav and audacity record work fine.
I'm under Ubuntu linux 12.04 64bit with kernel 3.5.0-40 and pulseaudio 1.1.