Hello all, I'm having trouble with my MacBook Pro going to sleep randomly. I will be working on the computer, and everything will go black. I can still here the computer running. When trying to wake it up from what seems like sleep, no buttons will work. The only thing I can do is do a hard shutdown, holding down power button, and then turning it back on. This originally happened about 2 months ago, and only once. Since about 2 days ago, it has been happening about 2 times a day. It occurs when the temperature of the computer is cold as well as when it is warm. I am not running too many programs when it happens. I have reset the PRAM. Any ideas / comments would be appreciated and helpful. Here are my system specs: 15 inch Macbook Pro 2.4 GHz Intel Core i5 4 GB 1067 mHz DDR3 Mac OS X Lion 10.7 Please let me know if there is any other information I can provide to help diagnose the problem. Thanks again.