I have an iMac 10,1 from early 2010 its running OSX 10.6.8. Originally the display would sleep after 15 minutes then the HD would sleep. Now only the display sleeps and it does it no matter what pretty much. If im watching a dvd, it doesn't recognize that and will sleep as if the screen is idle. I tried to change the energy settings but it keeps doing what it wants. How do I get it back to not only putting the HD to sleep when it supposed to, but as well as not sleeping when im watching a DVD/Video File?