I've had four of them. Is this a design flaw? After ~ 6 months but definitely 1 year (based on the age of each machine that I bought), esp. the right fan will start to fail. I can't define fail as stop spinning, but there will be a buzz-saw, grinding like the blades are hitting something, or a sound that resembles an approaching airplane (think WWII diving airplanes) that will continue to grow. It is audible at around 3000 rpm, and when you tilt the laptop at 45 degrees it seems worse. It's not a healthy sound. To hear it the best, run your fans at 6000 rpm and then slow them down to 2000 rpm. At 2000 rpm the fans continue to be inaudible. Unfortunately, it is this audible/inaudible combo that seems to make the problem more annoying b/c I can clearly hear the contrasts. If it was always there, I might be able to tune it out. This is not an isolated complaint about the classic mbp, but I've had so many of them over the last few years and all of them eventually exhibit this behavior. Every time I have taken it into Apple (about 3 different classic mbps) they have replaced the fan and said it was faulty. Whether they just wanted to make me happy or not is unknown, but a new fan did seem to help...until a few months later. I have never noticed this problem in my other laptop brands. I have taken apart the right fan and put some wd-40 on the shaft as others have suggested, and the sound still exists. It might be marginally improved, however. Do the unibodies exhibit this behavior and has this been a common complaint? I have seen the fans in the new unibodies and they are different than the ones in the classic mbp.