I get that, but only if I try playing two media players at the same time, or when I kill a player that has frozen, and then try play sound again. I think that when I use Xkill on a player, it also kills the sound daemon. Restarting X works for me though, although I have no idea why resarting X, which is for graphics, would bring back sound.
"Chopsticks require a person to use 64 muscles and 30 articulate movements simultaneously, which also acts in developing brain potential."