external drive ejects at sleep

The supplemental update to 10.8.5 did *not* fix the issue on my 2012 iMac. Although my WD My Book for Mac 2 TB USB 3.0 drive doesn't show the "improperly ejected" message, it still disconnects nonetheless after a few hours. Therefore, my Time Machine backups don't happen until I disconnect and reconnect the drive. Since my wife uses this machine much more than me, this means that it can go days in between backups, which kind of defeats the purpose of Time Machine! Thank goodness I also use Backblaze...

it seems, that Apple has only solved the problems with external thunderbolt-drives. This is at least consequent... 😉

Right you are. This was happening with my original 10.8.5 update, and the supplemental. I'm using an optibay so I can have two drives in my MBP, and the storage drive inside (without the OS) is constantly dissapearing. This is super frustrating. Anyone with suggestions? I'm downloading the 10.8.5 combo update and will try that.

I did install the 10.8.5 combo update on top of the supplemental update,still no joy.

I am hoping Mavericks will fix the problem,really annoying Apple mess...

Mavericks has fixed the problem, it's free as well!

Same here. Mavericks has fixed this issue for me as well

I take that back. I thought it was fixed, but I was wrong. In fact, now it's a bit worse. Now I'm getting the notice that "this drive has been improperly disconnected" again. So, again, my drive keeps disconnecting, thus interrupting my Time Machine backups.

The same here 😟

Same problem here. I have an external USB 3.0 WD drive and it ejects each time my new MBP 15" wakes up from sleep.

USB 3.0 too? I thought it was just Thunderbolt... all my Thunderbolt Raid drives switch off, and then switch on again when my 2013 iMac sleeps. Infuriating and worrying for the data.

Any updates on this. I just got off the phone with a Senior Specialist named Chelsea who claimed they know nothing about this eject issue! After 45 minutes she announced that is is probably the hard drive. I am running 10.8.5. I do not see a supplemental update at the App store. Any response would be appreciated.

Am minutes away from having an Apple Store swap my 1 week or so old LaCie 1TB Rugged Thunderbolt/USB 3.0 drive (the orange rubbery one!) with a new one, because it keeps ejecting. (Am using it with the Thunderbolt cable.) Thing is, so did my USB 3.0 1TB G-Drive Slim, which I assumed was a USB 3.0 bug also mentioned in another thread.

If this replacement Thunderbolt drive does the same, then we have absolute evidence this is an Apple problem.

(Am using a full spec late 2013 MB Pro with 1TB of SSD etc. Lovely machine, but buggy, even Adobe Premier Pro crashes on launch each time, and no fix from Adobe yet. Worked fine on my MacBook Air 13" mid 2011.)

No wonder my mum and uncle stuck to using a notepad and pencil!

I don't have the problem any longer. The drive crashed and is now going back for replacement. 😢

I have a Seagate 4 TB USB 3.0 drive that ejects when my Mac goes to sleep. I get the message about it being improperly ejected. I am worried that the drive will eventually have problems since it is always improperly ejecting. I am running Mavericks.

Yep, after countless improper ejections, I now see on startup: "The disk you inserted was not readable by this computer". Still having the same problem. One in 10 restarts it shows up. APPLE, PLEASE FIX THIS! Running 10.9.1