Recent comments are not showing up properly for users who have never made a comment. This seems to be a bad interaction between the latest version of WordPress (3.3) and the latest version of WP Super Cache (1.0).
The bug only affects lurkers, and only the more recent comments, but those are probably the ones you want to read. I am hopeful that this will get sorted out in the next bugfix release of the cache, which is due soon. It also think it may get somewhat sorted out as the cached files routinely refresh themselves. I’ve set them to expire on a more aggressive schedule in the hopes of encouraging that process along.
Meanwhile, if you can’t bear to wait until this is sorted out, I can offer the following work-around: point your browser at the Discourse.net comments feed. In most browsers you will be able to read the full text of the comments.
Later Update: I think what is happening now is that I’ve managed to club the cache tuning settings so that unrecognized users (ie those who do not have an ‘I’ve commented’ cookie) will get to see comments 15 or so minutes after they are posted. At least I hope so. I’m going to sleep now.