I got the sound to work finally by inserting "modprobe nvaudio" into the /etc/init.d/boot.local file. That loaded nvaudio and the other sound modules and I got sound working under X.
Curiously, YAST still doesn't recognize that a sound card is installed.
Also, inserting "alias sound-slot-1 nvaudio" into /etc/modules.conf wouldn't load nvaudio or the other sound modules into the kernel on boot. The solution above was the only I found that would install the modules on boot and get sound working under X.