Hey, I got my Mac Mini about a month ago now, and a couple of days ago I brought a 160GB External Hard drive for Time Machine. I don't like leaving the hard drive on when my Mac sleeps, so I turn it off to save power etc. but when I bring my Mac out of sleep mode, my mouse and stuff won't work, so I have to restart the Mac my mac by holding down the power button. This also happens if I switch off the hard drive when my Mac isn't asleep, in which case I have to put my Mac to sleep and wake it up again, then it returns to normal. Is this a problem with Time Machine, or just something I'm doing wrong? Any suggestion? Thank you in advance!