I received a new MBWE 500 GB few days ago and after struggling a bit I've managed to hack it and now I have done everything you mentioned in the First Steps section, and everything seems to work fine, except…
After let's say 20 mins, no matter if I'm copying some file or just letting the drive alone, the disk goes into a sort of sleep mode, and become completely unresponsive. The only thing I can do is to reboot the drive using the power button (keeping it pressed for about 5 seconds). Also, usually, this attempt of rebooting the drive fails (i.e. the drive seem to start, but then freezes with the leds switched off, and is not reachable via ssh), so I have to unplug the power chord, wait 2-3 mins, then plug it back and let the drive boot again.
I am sure it's not overheating that freezes the drive, it must be something to do with power management, I think. Googling around, I have found out that lots of other people have the same problem too with My Book World Edition, but I have been unable to find any solution to this problem.
If you have any idea of what's happening to my drive and possibly on how to resolve this issue, please let me know.
Thanks a lot, keep the good work!