Comment 91 for bug 537448

I found a blog with instructions on how to compile it and upgrade, although they're instructions for Karmic.
http://monespaceperso.org/blog-en/2010/04/17/upgrade-alsa-1-0-23-on-ubuntu-karmic-koala-9-10/

The sad point is that alsa-project.org is down by expired dns and http://alsa-project.org/pub/driver/alsa-driver-1.0.23.tar.bz2 can't be pulled ATM.