For those of us using WD MyBook Live, you may want to consider changing the default Twonky Media to DLNA media server using the instructions below. What I did not like about Twonky Media is that it creates its own folders and this makes it more difficult to navigate through all these folders.
The DLNA media server list the directories as is. It also works much better with the network enabled Blu-ray players throughout the house, which I use to access these files. After changing to this media server, it is important to then click on the Update Database button.