Comment 30 for bug 438318

Using the linux-image-2.6.31-10-generic_2.6.31-10.30~lp389040oga1_i386.deb from http://people.canonical.com/~ogasawara/lp389040/karmic/ as in bug #389040 (https://bugs.launchpad.net/ubuntu/+source/linux/+bug/389040?comments=all) made the internal speaker sound work for me (Karmic as in october 15th). So, I dont think it's a userspace issue... I think.

Anyway, with Lean's kernel internal speaker works, the headphones work, but the internal mic doesn't (although using a external mic work).

I guess it could be a good idea to use Lean's kernel patch in upstream (at least untill another solution is found), as Karmic release is on the way and no sound from the speakers will be a show-stopper to many users of this beautiful netbook (and this bug seems to affect the nb200 model as well).