First of all, I apologize in advance if this belongs in software. I couldn't decide which one was appropriate. I have a 2006 black Macbook. 2.0ghz, 4GB (upgraded), 160HD,27.21 available. The problems: I have a kernel panic once or twice a month. I get the spinning rainbow of doom frequently. Once a day or so, an application quits while unresponsive. The fan often runs REALLY loudly (I've had Macbooks for years [white, pro, a different black] and I've never heard fan action like this) The biggest problem is the sluggishness, though. I'd say about 1/3 of the time I'm using it, the fan is going nuts and it's SUPER slow. I'm talking can't-even-scroll-down-a-web-page-smoothly slow. The rest of the time, it's fast and quiet. Here's the thing: there doesn't seem to be any rhyme or reason to its moody bit. I can have 10 3000x2000 photos open in Photoshop CS3 and it's fine, but later that day I'll have Grey's Anatomy playing on the internet and it flies into its rage. What gives?