PhilK:
Interesting. I'd always assumed that comments were added en masse at the end of a Challenge; but from what you say, it seems as if they trickle through to the total while voting is still under way?
njrick:
The Library total increases each day, but the author's totals do not, I believe. Nor (any more) can an individual story appear with its total on the most commented list until after the challenge ends.
For normal submissions the comment count of the submission and the author's overall totals should increment dynamically at the time the comment is made (or where appropriate, approved). The challenge stories, however, all get initially loaded as 'restricted' which means the various comment totals only get adjusted en masse at the end of the challenge when the status of the submissions is no longer set to restricted.