I am having no luck with SR MacBooks. The first SR MacBook that I got from Amazon had multiple kernel panics [Disk Utility recently reported that the HD needed to be repaired], so they sent me a replacement MacBook. Now this one makes an intermittent grumbling/grinding noise that seems to be coming from the center of my keyboard. It's worse if I've been running the computer for awhile, and at that point, I can trigger it by opening webpages in Safari. As I had another SR MacBook previously [and my husband has the original MacBook], I know what sounds normal, and this does not sound normal. It's not a really loud sound, like the grinding noise my husband's PowerBook G4 once made before the hard drive died, but, it doesn't sound normal either. Does anyone know what this is?