Hi. I have some problems with my iMac. 1)Every night, I shut it down, before I go to sleep.In the morning, when I wake up, it takes me about 15 minutes of non stop pushing on the power buton to open it! 2)Another problem is that during the day, sometimes, my Mac may shut down by itself, and again, it takes me about 15 minutes to open it. Is the fact there are 10,17 GB left on my Mac, can be the cause for these problems? Can you please tell me what's the problem, and what should I do? Thanks.