Hi again markgrant, do you need to recover your files? If recovering your files is not necessary, I recommend you to try downloading the latest WD Drive Manager (Mac) 3.1.0 and try formatting the My Book. If you need to recover your files I recommend you to contact WD support for further assistance. You can also contact any of the WD data recovery partners, some of the offer a free evaluation of your drive.
WD Support
http://support.wdc.com/country/index.asp
Data recovery partners
