I have been using without problems for more than annyear. I updated mybook firmware and after that it does not show as a network share in wd tv live. This is solved if i turn off and turn on my mybook. After that it works fine, and after sometime (a day or two) it happens the same, Also would like to comment that have two different wd tv live in two different TVs.
Also check if you have the latest WDTV firmware update.
yes i have all latest firmwares.