Just caught the tail end of this and thought I'd add in my $0,02 worth of experience.
Using the latest Debian stable with KDE I had my PCMCIA sound come up "silent." Toying with KDE's controls and changing the sound driver and output (a confusing thing because there are multiple locations/widgets to do this) would fix the problem. At the same time the video (again, PCMCIA) would intermittently "blink" hinting at a driver issue. But sometime an apt-get update (or a reboot?) somehow seemed to fix things -- it no longer experiences those problems. -- "A king who does not protect the environment does not deserve to be called king." -- Chinese philosopher and politician Guan Zhong 700 B.C.
