I have(had) this problem. My MacBook had the case of the flickers. I recently got fed up and took it in, and sure enough they couldn't replicate the problem. So they took my word for it and replaced the inverter. Then something else happened. They told me my battery went haywire and started reporting that they had 4000 minutes remaining of battery life etc. Up and down up and down. So out of this I got a new inverter, and a new battery, all for free! I'm pretty happy, only until the flickers come back which I heard was common too... Anyone have any war stories about their MacBooks?