I have a 15inch Macbook Pro with the Core i5 and 256gb SSD. WHen I try to shut the machine down, it hangs on the blue screen and spinning circle, and I have to hold the power button down to turn it off. Also, I have an Apple Cinema Display and use it with the Macbook but only the monitor (mirrored display, then close the macbook lid). When I unplug the monitor and open the Macbook, it wont come back up, I have to turn it off then back on. Any assistance would be great.