This is actually a spam thread. Got the exact same flippin post on mine: http://search-engine-forums.webwobot.com/viewtopic.php?f=35&t=201  Same username too. After this one, there will come some spam. And then some more. I first thought it was actually a user, but then the spam came, and the same posts getting repeated across forum threads. 

I think there's another one that's become increasingly important, by the looks of things, and that's keyword proximity.

Blame Mott Butts for that! 

Indeed it is a subdomain, however it is the default subdomain. I don't think there should be a difference between having trailing forward slash or not, since I would imagine trailing slashes should be stripped out anyway. I'd strip them out.