I got a problem with shut down my mac mini OS X Yosemite 10.10.1. When I use a standard left corner shut down function everything seems ok until black screen and small process circle icon appear. After 30 min. computer is not turn off, white led still lights on mac. I have to do a hard restart. I try a few times and still same. Any idea how to fix it and make a proper shut down. Any ideas would be appreciated.