Deleting comments...

I'm really irritated that I can't delete what I believe is a spam comment from two posts ago. I didn't have the comment moderation turned on (though I do now!) and I read all the different ways to try to delete the comment and it won't work. I've cleared the cache. I've refreshed over and over again. I've tried doing the same thing in a different browser. And yet it is still there. It's one of those things (one of those obsessive-compulsive things) that really get to me. Short of deleting the post and then reposting it, I am not sure how to get rid of the comment. Grr...