I've heard from a ping goat rep:
"I would like to mention that pingoat is not perfect and does sometimes mistakenly blacklist some blogs.
However do to the overwhelming traffic we have been getting we have put up a forum for any of you to dispute your blacklisted blog.
here is the link to the pingoat forum:
http://www.pingoat.com/forum/
PLEASE NOTE: we DO NOT blacklist blogs simply because it is an adult blog, however we DO blacklist blogs that are obviously created via some kidn of content generator software. However most spam blogs use the words "Sex"...etc so the algorithm may sometimes have errors, but i invite you to handle your blacklisted blog properly, and visit our forum"