Well, that's an error from "the other side". There's no way of determining what it means from just the message except by guessing. My guess is that it doesn't like what you send it. Either it doesn't like the HTTP headers, or it doesn't like the content you send it. If I had to guess, my guess is that the other side doesn't like the absence of a particular Referer header. Or it might not like the cookie.

Abigail