If you type "cat /proc/asound/modules" you can see the current sound drivers.
It will also tell you the index (0 or 1) of the sound cards.
If you get the drivers right, after doing alsaconf, you'll see both drivers there.
If,after reboot, you only get one driver there, it's because you need to do "modprobe <name_of_driver>" to get it going.
The other problem might be that the system is treating one sound card as the default (the one with index 0).
If that is the case, it can also be solve easily.