I have a 13-inch Mid 2012 Macbook Air running 10.9.3. I usually run with the lid closed plugging into 2 Apple cinema displays. Everything works great, except when I accidentally bump the power cable, at which point it goes to sleep.
Is there any way to prevent this? Clearly it isn't a power issue, because with the lid open and no power cable it drives all 3 monitors just fine.