Post Text:
I had the same issue, but my drives were not MyBook units, just WD Green drives.
I had a OSX Mountain Lion where i’ve only used the Universal Firmware Updater, months ago. Not any other WD software and nothing in Applications from WD.
Upgraded to OSX Mavericks and then connected a Orico usb3 dock with two WD drives on it, one WD Green and one WD Red. The WD Green has been automatically formatted to a “MyBook” volume, while the WD RED is untouched with all his data. Then i’ve deleted the four WD files from /library/extensions and rebooted. Connected the dock with a new out-of-the-box (ntfs formatted i think) WD Green drive. The system immediately formatted it as a “MyBook” volume as well.
As for my experience, there is something left in the system from the WD firmware updater that act weird with OSX Mavericks and initializes any WD Green drive attached.
Probably a fresh install of Mavericks with no WD software on it is safe.
As for lost data, i encourage WD to give a working recovery tool, free and now.
User: seriously
Email: girovedogentefacciocose@gmail.com
Notes: This user does not have a My Book Studio II but is had the drives on a external encloasure and he experinced the same issue in two WD Green drives.
