We have been having HUGE problems with the digests, unfortunately, I've been working on it nonstop (literally) since Monday night. The last one is all screwed up? That's terrible as that means it's the last one that went through. You got three within the past 3 hours? I'm really sorry about that! This is such a disaster. :(
Are you sure you didn't receive two, Davey? The first one you received back when I was having crazy problems and it was all just completely hit or miss. I think only about 15% of the people got it, and sometimes they got jibberish or a blank email. What a disaster!!
Then when I figured out all of the problems, I did a complete blast for everyone from start to finish. So you should have gotten this as well.
It's very probable that your subscription mailings are just a little slow because the server is busy processing close to 150,000 newsletters. Let me know if things don't return back to normal by tomorrow.