So far my i5 has been a pleasure to own. I originally had a release week C2D that I ended up returning because of yellow screen and Seagate hdd problems. I Just got this i5 that was built the first week of April and it is gorgeous compared to the original 27" I owned. The problem is I cannot get it to boot from USB or from the Superdrive. It boots to the internal WD drive perfectly. I have been trying to get it to boot to a Tech Tools Pro 5 disc to runs the tests on it, but haven't been able to. I did a restore of the disc image to a usb drive, and that boots perfectly on my MBA. I have also tried to boot the retail Snow Leopard disc that I bought to upgrade my MBA and it will not boot either. In all situations it hangs at the grey screen with the apple logo. These sources all show up and can be selected from the boot options screen (holding OPT at start up). Both the discs boot perfectly on my wife's 13" MBP. The funny thing is, however, I can boot from the OS X restore disc that shipped with the computer. Hardware wise, everything checks out. I did notice though when trying to boot from USB, the USB drive (8gb Sandisk thumb drive) lights up when its plugged in and shows activity (flickers) at the boot option screen, but the light goes out as soon as that drive is selected, leaving me to believe the drive is no longer receiving power. Once again, I can boot from the usb on my Air with no problems. I am stumped. I have wiped the OS clean and reinstalled Snow Leopard and nothing changed. The fact that the USB drive loses power makes me wonder if it is a firmware issue and or a bad Superdrive. Not sure where to go from here, short of loading the sucker into my car and taking it to AppleCare. Thanks in advance, any insight/help is appreciated.