Hi all, A few months ago I had to replace the fan in my MBA (rev D). I've noticed that the new fan seems to spin up to a higher RPM with much greater frequency than the old one did. (For instance, as I've been writing this post, the CPU has been 95% idle, the CPU temp has been in the low 70s C, and the fan has been running noisily at 4000-5000 rpm.) I'm acutely aware of fan noise issues because this is my third MBA. My experience for the first year of owning this machine is that it had run much more quietly than the previous two machines, and was also greatly improved in terms of the fan slowing down after the end of heavy usage. Now it's like I'm back to running a rev B. Any thoughts on what could be going on here?