Hello, I purchased the older dual 2.0 (2499 model) after the new ones were announced. (could not pass up the price) Anyway, it was factory sealed unit. When I put it to sleep, I would say, one out of every four or five times, it makes a fluttering noise. (definately audible) On top of that, about every four or five times when waking from sleep, it goes right back to sleep and I have to hit return again? It passes the hardware test just fine, and the ram is just the factory ram from Apple. Any ideas?