So, I recently went from the white plastic macbook, to the unibody macbook. With my first macbook, if my computer was open and on (unplugged), it would go to sleep and conserve the battery so you could just wake it up. However, 2 times already my unibody macbook has gone completely dead just sitting open in sleep mode. Has anyone else experienced this? It is really not a huge deal, I just want to make sure my new computer isn't defective.