OK, this is a new one on me. I have a BlacX USB 2.0 SATA dock thing attached to one of my machines and I have several 1TB drives, which I swap every few days. I have some scheduled tasks that copy stuff to whatever drive is currently there ("G:") overnight. The problem I have started noticing is that when I will go to swap the drive, I will want to use the "safely remove hardware" to eject it first, however sometimes it has just disappeared from the task tray. "Eject" is not a choice in Explorer either. Somehow the drive has magically decided it is not removable anymore! This doesn't happen immediately, right after a swap the wizard is there and offers to "Eject JM20336 SATA, USB Combo" but after some unknown amount of time it is not removable anymore. At this point the only 100% safe way to swap the drive is to reboot the machine and eject it from the dock before it comes back up. Any ideas what is going on? Edit: I should also mention that because I keep one of them offsite or in my car, these drives are encrypted with BitLocker, and the machine is configured to automatically unlock them when connected.
Or it might just be bugginess in the OS or drivers. I've had weird problems before, like a piece of hardware is no longer removable after a removal and reinsertion. As for ticking the quick removal box, that just controls caching and makes it safer to do a surprise removal. A drive should still be removable even if quick removal is unticked. IIRC, hibernation should flush the buffers, so you don't necessarily have to go as far as rebooting.