For a while I had been running my Macbook Air at 800Mhz with CoolBook without any core shutdowns or crashes. It was only until recently that I decided that I needed the speed so I set it back to its normal speed. I noticed that the MBA can't take high cpu or graphics load because it shuts down one core and slows the other one dramatically. I use this computer for work and I can't do anything without a core shutdown. Even watching a movie will trigger a core shutdown. A video conference in iChat is enough to make it become useless. I called AppleCare and sent it in and now they're telling me that the "technicians cannot replicate the issue", which is crap because it definitely overheats. So now they're telling me that there is nothing wrong with the computer and they want to send it back unrepaired. I also noted a loud beeping noise that the computer sometimes makes and the technicians completely disregarded the issue. This is ridiculous because I'm not asking more from this computer than the specifications provided by Apple clearly state. I'm not overclocking it or running it at over 100% of its capacity. It should be able to handle 100% of its stated capacity. If this is normal for the Macbook Air then they should have clearly stated when I bought it "this computer is only fast for two minutes" or "this computer is only meant for light use". I can't even watch a movie rented on iTunes when Apple clearly suggests it as the way to watch movies on the Macbook Air.