Upvoting not working on certain comments

Tested this out on other articles (works fine) as well as other select comments within this section, upvoting works fine, but it won't work with certain comments.

@xantufrog Did you edit your comment or anything? As this is raising an eye-brow when taken in context with the article.

@uninspiredcup: Can you link me to the specific comment that it's not working on? I can take a look.