MSN Censoring???

Ooookay, this is weird: Try IM'img someone with the following URL on MSN: http://2www.007b.com/breast_gallery.php Guess what? It won't go through. Take the b-word out, though, and it does. Or change the domain. Do they have some weird URL censor?? I'm using Adium on the Mac, so I'm pretty sure the censor's not there. My wife has MSN on Windows, though, so it's possible that it's her MSN client (no, we don't have any parental controls on the computer - there's only adults in the house). Very weird. AIM works just fine for the URL, though...