Hmm looks like I hit a bees nest there. I searched a bit and found out something more.
My onboard sound card + alsa is the problem. It's a VT82C686 which uses AC97. This has no mixer and I read here
http://www.osnews.com/story.php?news_id=8823 under part 4 that there's the "aoss trick". I didn't get much by googling around except that someone mentioned it related to using a wrapper.
I don't have time now to check it out and do that but has anybody got it to work this way?