Apparently, some malicious code crept into my blog, and disabled a number of connections called “permalinks”. This resulted in comments being disabled, as well as email notifications being scrambled.
I have fixed the problem, but only through complete cleansing of my site. In the process, I deleted all subscribers. You will need to re-subscribe and request notification of new posts if you wish. Also, the process of adding old posts back into the blog will take a while, so we are seeing only the most recent posts for now.