I recently purchased a June 2013 MacBook Air running Mountain Lion. Around the same time, I purchased a 1 TB Seagate external hard drive, which I partitioned into a section to use for routine back-ups with Time Machine, and a section for extra storage. It connects via USB to the MBA. The hard drive works fine, except for the fact that almost every time I put my computer to sleep, when I open it back up, I get the ominous warning message informing me that the external hard drive was improperly unplugged without first ejecting it, damage may occur, etc. When I look in Finder, indeed the hard drive is no longer mounted, even though it is actually still plugged in. I then have to unplug the hard drive and replug in order for the drive to mount again. Is there some setting that I can change to stop the hard drive from disconnecting whenever the computer sleeps? The only other alternative I see is somehow make myself remember to eject the hard drive before I close the lid of the MBA every single time I do it, unplug it, and then replug when I start it back up, which is a huge pain given that it is a portable computer that I use all day in various settings. Any help would be much appreciated!