I have a hp pavilion dv8000 and the sound does not work also. I read at another place the vista 64 sound driver would work but no luck yet. They said to updte driver and find folder where you douwnloaded it to.
I tried about all the drivers. Nothing was working. I downloaded the 32-bit version and installed a fresh copy. Everything worked. The sound is working. That's the only thing I can tell you is if you are running the 64-bit version switch to the 32-bit version. It worked here. Let me know how it works.