Interesting problem has arisen with two of the plug ins I run on my Canadian Personal Finance site.
I added the commentluv plug-in a while ago, where commenters are invited to include a link to one of their posts on their site. I like this plug in as it is kind of cute, and the links put into the comments are actually “no follow” so it doesn’t hurt me much either.
I also run Akismet comment spam checker and it does not seem to like commentluv at all. Luckily I check the spam queue before I flush it each time (this plug in has caught over 11,000 spam comments for me, so I do highly recommend it), and I find a bunch of comments from regular commenters in the SPAM queue, because they had used the commentluv post capability as well.
My guess is Akismet sees the link in the comment assumes it is SPAM and throws the comment out. Hopefully it will learn not to do this, but I will need to watch my SPAM queue a little closer for a while is my guess.