I just bought a Rev. B Macbook Air from ebay, used but in good condition. Since it's been used for a couple of months they would have noticed any problems it might have. They seem quite trustable(member on macrumors actually) so I don't think they're hiding anything. So assumable it's a software problem, since they wiped things out to their defaults before shipping it. The problem is that the computer keeps going to sleep after only a second or two. At first I didn't have this problem, for a couple hours in OSX. Then the next minute I woke it from sleep and in a couple of seconds the screen went out and it went to sleep again. So I woke it up, and again it went to sleep. When it wakes up it flashes a blue screen for a second before fully waking. I tried restarting, didn't help. I booted into safe mode and the problem was gone. While in safe mode I made sure the energy saver preferences were set to the default. Rebooted normally and the problem was still there. Also tried resetting the PRAM, didn't help. I was thinking its probably a hardware issue(sensor for if the screen is closed or not) but that wouldn't match up with the previous owner not having the problem, and the problem disappearing in safe mode.