Well, this hosting provider appears to be a loser. This time around, I'm not mentioning names, but it shouldn't be too hard to figure out who they are.
Their ftp server seems to be out in the weeds. The List is supposed to be updated every hour... as long as there's an ftp server on the other end. Right now, it's been almost three hours since the List was updated.
I send a SYN for the three-way TCP handshake and nothing comes back. They assure me there is no issue on their end. Then, if you do some troubleshooting on your end, like scanning port 21 to see if it's open, they block your IP. I'm not kidding.
In fact, I've taken to viewing my own List over one of the many fine Glype proxies out there (NoScript and Ad Block enabled) just to keep my connection count down with their servers.
This does solve the problem of list scrapers, which I never really considered a problem. If you snarf the whole list down with a wget script, you'll exceed their limits and they'll block your IP.
So right now Wireshark's been running, collecting data on every update run.
It doesn't look good.
To be fair(-ish), these folks have had serious DDoS issues in the past, so they're in paranoid overkill mode on the security side. But the result is they're DoS'ing their own customers. Very strange business model.
I have some options, but I expect the same results. I didn't mess with them over the weekend because, for one, they kept blocking my IP, and two, I was preoccupied with rebuilding my system, which died right after I started bringing the site back (moving XP to another physical box—without reinstalling—is always fun).
Anyway, I can live with the failed updates for a few weeks while I look for another provider. The collection process runs as it always has, so I have the data, even if you don't.
I'm open to suggestions, but I'm leaning toward BlueHost.