Just want to say, if it's a heat issue, I'm running Peppermint OS (which is a Ubuntu variant specifically optimized to run on low-power/low-memory computers) and it runs much cooler than Narwhal did. I wasn't getting shutdowns on my Narwhal netbook, but I was getting what seemed like heat-related problems, and they're better under Peppermint. Even when I leave it on all night!