Solution to Ubuntu's crackling sound

I encountered this problem when I first upgraded to Ubuntu Intrepid Ibex, when ever a sound should be a playing, one can only hear crackling sounds. It appears for some reason pulseaudio occasionally turns the pcm volume to 0 which causes pulseaudio to make the crackling sound when sound is played. I havent been able to figure out what caused it as its only happened once on upgrade and a second time out of the blue. It hasent happened since.

Solution is either to simply use gnome-volume-control, alsa-mixer or any other volume apps and increase pcm volume.