WD My Book world and Mac Lion - dropping connection

I have a WD My Bookworld white light NAS drive. I have had this wirelessly and wire connected (ethernet to router) to my MacBook for a few years (On Lion and now Mountain Lion). It works well as a back up drive with time machine. However, from time to time it drops its connection and the Mac can not see the drive. 

When this happens the only solution is to turn the WD drive off and on again. The problem I am looking for advice on is that after the WD being switched off and on time machine wants to back up best part of 100GB, when I know there is only a small amount of data to be backed up. 

Any advice on how to resolve this connection issue and how to prevent losing any previous TM back up (given the previous back up is still taking up memory space on the WD drive!)

Whenever this starts to happen it means the controller card is about to fail

backup all data and consider upgrading your drive

Thanks for the feedback. I dont really understand what that means though? I am still able to enter time machine and can see up to date back ups even though the back up says it was unable to complete. 

I don’t think it’s the controller card. People all over using Lion are having this problem. Here was mine…


…and now Lion is deciding it doesn’t like my Seagate, either. From what I can see, Apples just absolutely hate NAS drives and want to be connected on a wired connection to them. Which would be great, if there was more than one Ethernet port on the back, because I need one for the modem. Sigh.