It still fails.  It also plays a bit fast (HAL the computer sounds
   like one of the Chipmunks).  It only gives the out of paper message
   the first time, though.

That's what I'd expect if the sound card is configured for IRQ 7, and
you have the interrupt enabled on the parallel port.  (Actually, I'd
expect `offline', but different parallel ports have different states
when there's nothing connected.)