mplayer locks up sound sometimes; have to reboot to get sound back

[inkbrush]

Hi,
Linux newbie here, trying to learn Fedora Core 4. I installed mplayer and other software folloing Stanton Finley's instructions. http://stanton-finley.net/fedora_cor...ion_notes.html
I have been having lots of issues recently. One of the most annoying problems is with mplayer. Sometimes, for reasons I don't understand, opening an mp3 file that usually works fine causes mplayer to freeze up. Afterwards, the sound stops working completely. When I try to use other music programs like xmms, I get this error:

Couldn't open audio

Please check that:

Your soundcard is configured properly
You have the correct output plugin selected
No other program is blocking the soundcard

Basically, my sound is locked up for some reason. I have tried logging out and back in, which doesn't work. I also tried logging in as another user, which doesn't solve the problem, either. The only way to get sound back is to reboot.

I would like any help in preventing and solving this hang-up. I am wondering if there's something I can do to restore sound without having to boot-up again. Thanks a lot.

[inkbrush]

In case some other people are having the same problem as mine, I am posting what I did to get sound back. When I first installed FC4, the default Alsa sound driver would not play sound from the CD drive, so I switched to OSS using the Gnome Configuration Editor. Today, my sound locked up again when trying to use mplayer, so I tried switching back to Alsa and I got sound back without having to reboot.