If you are feeling especially adventurous, you could download the latest beta release of alsa and compile it.
If you go that route and have any questions, go ahead and post here and I'll get you through it.
That should get the sound working.
Either that or spend about $20 for a standalone card like the Chaintech AV-710 which is very well supported in linux.
Here is a link to a sound card roundup under linux. For those that don't know, Phoronix is a linux hardware/software review site.