Well, we checked everything today, and there is still a problem with comments on my student's blog. I have contacted people at eslblogs, and I hope that when they are finished with a database upgrade, things will be better. In the meantime, please feel free to comment on his blog but know that your comments may not/probably won't show up on the blog itself. He is getting comments emailed to him, though, so he will know what you are saying.
He was, by the way, quite happy that people had read his blog and commented. So thanks from both of us!
As an aside, I talked to him about moving his blog to WordPress, but he would prefer to stay where he is. As I have said before, he is a little afraid of blogs, so I didn't push him on it. He is so happy with this project so far -- in spite of the problems -- that I don't want to mess with it.