I called Dish about my 721 having this problem. The first tech said they had gotten a note about the software problem and are working on a solution. We got disconnected when he put me on hold for something.
Called back. This girl sharply said, "I've never heard of it". I said there is supposed to be a tech note about the software problem and again, she said sharply, "I've never heard of it and my supervisor doesn't know anything about it". Then she said, "Oh, this has to do with the Tivo lawsuit, so we're going to replace your unit - hold on while I get the info..." She was talking so fast, you couldn't get a word in edgewise.
I said, "Wait just a minute - you're going way too fast. What replacement are you talking about?". She said, "We're going to replace it with a 522..." I said, "No, you're not - that's a downgrade and requires a DVR fee. You aren't letting me finish any sentence and you don't even know what problem I'm talking about." (She was constantly and forcefully interrupting me.)
She said (strongly, for some reason), "Then that's all I can do."
I said goodbye.
Meanwhile, my Dish service is almost unusable, since the receiver has gotten worse. It's cutting out more often.
By the way, I've not had the same luck with my 721 that others have had. This is my 4th unit in about 5-6 years. Hard drive failures.