Can't recover sound

[Victor Munoz <vmunoz@macul.ciencias.uchile.cl>]

Hello.

Sometimes I can't hear any sound (xmms, mplayer, play), getting things like
'Device or resource busy'. This happened in woody, now in sarge, sometimes
in sid, and everytime it happens, I do a Google search to try to find a
solution smarter than rebooting, but never find an answer, so I have to
reboot.

So the question is: How can I recover sound in this situation? Yesterday it
happened, for instance. There was no xmms, mplayer, play, skype, realplay or
whatever I could remember involving sound running in the background. I don't
run esd. But still, I could not play any movie or hear any sound from xmms.
I tried removing/reloading sound modules, but everytime I tried, it
complained that the module is being used and cannot be removed. There
doesn't seem to be a rmmod -f option. 

Is there a way to know which program is using the sound modules, so 
I can kill that, or any other way to recover a 'clean sound state' without
rebooting? There should be, but Google has not been my friend, probably for
my inability to make the right question.

Regards,

					Victor