I just spent about three days fighting the Lenovo 3000 N100 laptop. I've also seen post from other people having the same problem. The most difficult part was the sound. I've finally found a page with the workaround and the patch. Since the patch is just adding another PCI device info to the existing intel hda driver - it should be safe to incorporate it into Gentoo.
Here is the page:
Here is the URL for the patch:
Sent upstream, waiting for them to accept
Fixed in gentoo-sources-2.6.17-r1 / genpatches-2.6.17-1