MacBook no longer shows WD TV Live Plus in the finder - what the heck?

When I am using my MacBook and turn on my WD TV Live Plus, it no longer appears under Devices in the Finder. This was never a problem previously. 

I can still sometimes get it to appear in the Finder if I leave the WD TV on and reboot my Mac, but I shouldn’t have to do this. It should appear in the Finder automatically.

Why would this be happening? I am running Lion and have been since last summer. This problem has only started happening recently.

I would try resetting the WD TV by holding its reset button for 4 seconds.  You may also try accessing it from another computer, in order to compare results.