Comment approval has been a real pain. I found two or three of my own comments that haven't gotten through. The present system allows for no filter whereby a previously approved address might continue to be approved.
That said, please let me know if you don't see your comment after a day or so. There are very few legitimate comments that I do not approve. In the entire time I've run the blog I can think of three that I have had to delete for unsuitable content that were really comments on the material at hand. So, I'm not trying to prevent anyone from having their say. In fact, my theory of blogging (and perhaps one of the reasons this blog is so sloppy at times) is that the blog is an invitation to conversation. If your comment doesn't make it, there can be no meaningful communication.