I think I can help you here.
It's a common problem with sound cards like this one, and I know since I have the same card. Apparently, the alsa-driver
is having a hard time with this model and needs to be patched.
I'm using Fedora 7 (with ALSA version 1.0.14) and I got the sound working by following the solution here: http://paparadit.blogspot.com/2007/0...mate-6291.html
(scroll down to the bottom of that page and follow what is written in the second comment)
If alsamixer shows that your sound is not muted, try that solution. I'm pretty sure that it'll work with openSUSE as well.