I'm a bit pissed off with them. It turns out that they've got Pocus' website in their list of spam sites. I'm not really sure why but there you go.
Anyway, the upshot is that if I put it in as my linking site in the commenting fields (and it defaults in because I did the first few comments I made) Wordpress simply deletes my comment. I don't get a message to make it clear why, it just goes.
Pretty crappy really. I've asked them where this list of spam sites is kept so I can refute it but they've remained silent. Anyway, be warned. Don't put a domain in to that box just in case it decides you're a spam bot and eats your comments.