Audio on BeagleBoard xM and Ubuntu can't work (1738841)

Hi, folks,I'm trying to play audio on my beagleboard-xM. The operating system installed is Ubuntu for the ARM cpu. I've tried installing ubuntu on two sd cards,with two different kernels (3.0.4-x3 and 2.6.38.4-x3),but the problem is not gone. (with the Sakoman Linux everything works great),but I haven't been able to hear any sound and there are no visible errors involved. Someone suggested that it could be caused by a bug,as it is explained here : https://bugs.launchpad.net/ubuntu/+bug/651302 I attached some relevant picture. I start this project to fix this bug as soon as possible. Thanks.