I've been observing my SR MPB for the last few days, and I noticed that my fans are activated by high memory control temperatures, not CPU temperatures. Right now I have firefox and word open, the CPU temperature is 42C and the memory control is 60C, the fans are spinning at 4000 RPM. A few minutes ago the situation was the opposite, I was ripping a DVD, the CPU was at 62, the memory at 52 and the fans at 2000 RPM. I think that's where all the complaints of people scared about high CPU temps and low fan RPM are coming from. People freak out when they see a relatively high CPU temp with a low fan speed. I noticed that with a low memory temperature, my fans only speed up when the CPU goes over 65C.