It seems I had similar problem with sound device. It seems I have solved it..
Try to send a wav file using play command, it will output an error, which is ok.
and then you should be able play musicCode:play /opt/harddisk/music/some.wav -d /dev/sound/dsp
more information about my problem is here http://diy.sefikuv.net/asus-500g-del...ng-tenx-tp6911