No sound after 4.0.1 upgrade

[Baruch Chaim Stone]

Howdy folks. Here's another one with no sound after a 3.0.1 to 4 
upgrade. A few things:

1) I have no confirmation I am running 4.0.1 vs 4.0. When I boot it says 
4.0 Orion, but running yum upgrade with multiple mirrors does not yield 
any further available upgrades. Any idea how I can easily tell if I am 
using 4.0 or 4.0.1?

2) My kernel was still 2.4.x. I manually upgraded it to 2.6.10-1.ydl.1 
and that went well.

3) I have no sound, other than this loud "BEEP" every time I get a new 
email in Thunderbird

4) In Gnome, going to System Tools->Sound Card Detection works as I can 
hear the lovely guitar strum

5) Following the instructions at 
http://www.yellowdoglinux.com/support/solutions/ydl_4.0/audio.shtml 
tells me to open a shell, su - and this is what i get:
 

> [root at localhost root]# alsamixer
>  
> alsamixer: function snd_ctl_open failed for default: No such device

So, uh, help?

Thanks!
baruch stone