LOL it's like wp 1.3 or something so more than likely but I give out the dofollow links freely so no one really wastes their time exploiting it. and ya there have been quite a few posts on top commentator hijacking.Didn't read the whole thing but i took at look at your site and its got a vulnerability in it that "could" allow me to get some of that fine link juice you seem to be sitting on
Anyways, its given me food for thought and I just might write an article on my blog about how we can use these methods to grab link juice from sites with similar vulnerabilities.
Anyone interested in reading this type of blackhat SEO stuff?
btw: feel free to pm me and I'll let you know where it is...