I have to admit to this guilty sense of relief that this problem, at least, probably isn't my fault...I'd say that something wrong at your friend's end is triggering the correct response from the site.

As the message implies, I put in safeguards to prevent automated spamming of the boards. That's a classic, and very basic, way of attacking an Internet site--choke the site with messages it's designed to handle, a form of denial-of-service attack that can deny use of the server to other people, and at worst crash it.

This presents a tricky problem for me: In order to diagnose what's wrong, I have to reveal how the defense works. How about switching this conversation to email?