Weird sound problem

Hi guys, On my Compaq Armada m700 notebook (P-III 1ghz), when I play music with xmms, or movies with MPlayer, from time to time the sounds just stops, and the application hangs, until I press any key on the keyboard. Then it continues as normal. This is in SUSE 9.3 Pro, all updates applied. It also happened Debian Sarge and Etch, so I don't think it's a SUSE problem. Any ideas? The soundcard is an ESS maestro: 0000:00:08.0 Multimedia audio controller: ESS Technology ES1978 Maestro 2E (rev 10) Thanks Hans