My apologies that some recent changes in typepad seem to have created a number of problems related to comments.
One is that spam comments started taking over the "Recent Comments" box in the sidebar. Typepad are working on it, to reduce the problem I have closed comments on all posts older than 6 months and I re-instated the "captcha" for everyone (I am trying to remove this again to see if it is causing some of the other problems).
Typepad are also trialling a new comment editor where comments should display immediately. Clearly this is causing people to accidentally leave comments multiple times. Don't worry, I will clear up such problems (for everyone but Richard).
Hopefully things will settle down sometime during this millennium.