Yeah, my WD MyBook Essentials 750GB worked just fine for a few months and then one day, out of nowhere, I could see all the recordings but could neither watch them nor restore them. Bye bye.
Time will tell if they have fixed the problem with this new drive. At least, with its being "certified" for Dish DVR use, you can get a refund or replacement if it goes south.
.....G
Same problem here, too. Exactly.