I had Time Machine working fine, until I got a message that it needed to create a new Time Machine Backup. Now everytime I try and do a back up, Time Machine disconnects the My World Book from the network. If I reset the box, I can access the Public Shares again no problem (apart from iTunes 10 grief!), but if I try to start Time Machine again, the whole WD disconnects. MY WD drive is fully up to date firmware wise.
MacBook Pro running 10.6.4
Out of curiosity, I decided to try with a trial version of chronosync, backing up to a folder on the Public drive, not to the Backup.
Same thing happened, after about 30 seconds of starting, I lose the connection to the My World Book. So it would seem to be a WD issue, as apposed to a Time Machine issue.
Maybe you should try contacting WD’s Technical Support about this. You can do so either by phone or email.
To Contact WD for Technical Support
http://support.wdc.com/contact/index.asp?lang=en
To be fair to WDS Tech Support (UK), they sorted my previous problem with the NAS pretty quickly (rubbish memeo Mac software).
Haven’t had time to call them yet as I’m working away from home and (my only gripe) is that Tech support are not available at the weekends. Because nothing EVER goes wrong at weekends, does it? 
markso wrote:
Out of curiosity, I decided to try with a trial version of chronosync, backing up to a folder on the Public drive, not to the Backup.
Same thing happened, after about 30 seconds of starting, I lose the connection to the My World Book. So it would seem to be a WD issue, as apposed to a Time Machine issue.
Unfortunately, I am unable to reproduce your problem. I do have some questions that might help me figure out the difference between our setups.
Do you have any other network devices or computers on your network?
Do you have all system updates applied to your Mac?
What firmware version are you running on your My Book World?
What brand and model of router are you using?
Do you have any Ethernet switches or hubs on your network? If so, what model are they?
Is your Mac connected via wired or wireless connection?
How much free space do you have on your My Book World?
I hope this information is enough. If not, I may wind up coming back with some more questions. I wish I had a better answer for you instead of just questions.