I had the same problem as you did, except I was using two audio card, the onboard and a SB live. I took me 4 hr to figure out how to fix that problem. Here are the step I finally found:
Note, this is not the best/ideal method, but it worked for me.
1- Go into yast-->hardware-->sound, look at the driver name. In my case, it was snd-hda-intel
for motherboard audio snd-emu10k1 for the creative lab PCI-card.
2- Exit yast
3- Go at the shell (right click on the desktop-->open Terminal)
4- Log as super user (enter ¨su¨) and enter your password
5- Go to the directory with the config files: ¨cd /etc/sysconfig/hardware¨ (this is the folder
that took me very long to find)
6- Find the file that hold the driver: ¨grep -i snd-emu10k1 *¨ the filename containing the
7- move that file somewhere else as a backup (who knows, you might do a mistake)
9- Go into yast-->hardware-->sound, the audio board should have bee re-discover, do edit and
then test if the audio works.