I have a 2 month old MBA rev C 1.8. I went to use my machine that is running really hot all the sudden and I noticed that my machine won't run any lower then 1.8mhz. It used to throttle down all the time and now it wont and is running very hot because of this. I checked activity monitor and nothing is taking more then 3% usage. Nothing spiking it up. Anyone help out with what I could do? -Turns out my printer driver was spiking the processor. I didn't realize when looking at my activity monitor that I was only looking at user processes and not all processes. Reinstalling the printer fixed this. Thank you for your help ayeying.