I contacted Laurel, the head honcho (I believe!) at Literotica, and that appears to have resolved the issue.
Succubus Summoning 213 is now up here and the Cnidarian-Girl story is scheduled to go up tomorrow (I also have the accompanying profile ready to go up on the blog tomorrow).
I'm not sure what happened - gremlins in an automated checking system, overzealous mod with a grudge on a power trip... Laurel mentioned they've been deluged with submissions recently, so I'd rather believe it was the former rather than the latter (plus tinfoil doesn't really go with the rest of my outfits). If any of you out there are having similar problems the best thing to do is drop Laurel a polite PM through the site's messaging system.
The good news is that it appears sexy succubus murder-death-kill-by-snu-snu stories are still on the menu.
It also means I don't get to look like a money-grubbing ass for making my long-standing Lit readers wait for the ebook in order to get the last chapter. It might cost me a few sales going up on Literotica first, but to be honest, most of you have shown enough willingness to support me by buying my books when they come out that I'm happy to keep posting my work up on the internet.
And now I'd better get back to getting that ebook version of Succubus Summoning 201 ready...