Re: Stability Problems amd64
first of all, don't ever use the installer on a gentoo system.
You had api mismatches - if you use the ebuilds, this won't happen. Also some apps don't compile against the nvidia libs, and when you use the installer, you can't switch easily.
Do you have two cards? If not why are two in your xorg.conf? Oh, and try re-setting the card and try a different PSU.