After upgrading to gentoo-dev-sources my nforce network and nforce audio stopped to work. Device were created in /dev/ and I can manage eth0 (nforce network) with ifconfig but nothing works. I suppose that it is something like this http://lkml.org/lkml/2004/6/6/55 and this http://lkml.org/lkml/2004/6/6/58 . Here you can get my dmesg and lspci http://forums.gentoo.org/viewtopic.php?t=187788 .
Ok, then this is a upstream acpi bug. Please file it at bugzilla.kernel.org.
I got my system work disabling USB 2.0 support on my kernel as reported in this bug: http://bugs.gentoo.org/show_bug.cgi?id=54413 .