I just rechecked the situation: In fact, "simply" killing my sound apps, removing the modules, going into suspend, coming back, reinserting the modules, restarting the sound-apps does the trick. But still, you wouldn't want to do that after every MPEG3 title you play... (BTW, even if I start, say, x11amp with a list of more than one title to play, sound stops working when the first title is finished and the second begins. Still no error message, just no sound output anymore...)
Stefan