Until upgrading to the 220.127.116.11-27 kernel today the sound on this laptop (Lenovo 3000 C200) has not been working.
Since the update all I had to do was adjust the volume in the mixer applet and my sound now works. This is with the 82801G (ICH7 Family) rev02 identified by lspci. Might be worth trying if you have had this problem.
I've checked back to the 21-.1-3228 kernel and it's still definitely not working so there is a difference for this device in the new kernel.
A word of warning though. I found the hard way that the microphone boost in my mixer was set to maximum as a default leading to uncontrollable levels of acoustic feedback as I rebooted the first time I used it. To the extent that the sound production devices were causing hotspots on the case before I could get to the controls to turn the levels down.