I have the Inatek 4004 and it ejects my USB drives when my 4,1 goes to sleep. I've had it corrupt a single drive so far doing this.
I have Jettison installed now to eject the drives before sleep.
Annoying.
As annoyed as you are, it's not the card that causes this. It's the OS mostly. It's fairly well documented. Mac Format recently addressed the issue and explained that it's a combination of the OS X sleep routines and the drive's (to include the drive controller) sleep routine.
Now I'm not sure that is the correct answer. I also had the same issue with a MicroNet Fantom USB 3.0 HDD connected to the Inateck KT4004. That drive, could also not figure out whether it was a USB 2.0 or a USB 3.0 Device. On Start-Up, under System Information, it would show up both ways depending on it's mood. In frustration, after about 6 months of ownership, I finally returned the HDD to MicroNet. They found nothing wrong with the drive. After much eMail arguing, they finally issued me a credit. However, I was out the 13 bucks it cost to return the drive, and the frustration and time wasted using it.
I replaced it with Hornetek Viper USB 3.0 enclosure with a fast Seagate HDD. That combination, always starts up and acts like a USB SuperSpeed Device, and it has never once ejected itself from the USB 3.0 Card.
So, I believe the issue is not with Apple, but with the electronics employed by the manufacturer of the external drive or enclosure.
Lou