The comment which I am replying to by tptacek currently demonstrates undesigned behavior which I have seen on other pages: to the best of my understanding, highlighting is done on a per-poster not per-comment basis, yet highlighting behavior is inconsistently applied to highlighted posters. You can see tptacek's comment earlier in the thread which is highlighted, while the parent comment of this comment is not. (Further, the parent comment is actually highlighted on the reply-to screen.)
Not too important but, to quote our house dev motto, "behavior contrary to specification mandates a bug report no matter how minor the deviation is".
[Edit: I refresh this page and am seeing it sometimes highlighted and sometimes not highlighted, so I'm not sure if my bug report is accurate or not. Apparently the Heisenberg Uncertainty Principle applies to bugs: attempting to describe one changes its behavior.]
I think this is explained by a previous news item on the linked page. pg talks about introducing lots of caching to speed the site up. Sounds like you're seeing cached bits and pieces.
Not too important but, to quote our house dev motto, "behavior contrary to specification mandates a bug report no matter how minor the deviation is".
[Edit: I refresh this page and am seeing it sometimes highlighted and sometimes not highlighted, so I'm not sure if my bug report is accurate or not. Apparently the Heisenberg Uncertainty Principle applies to bugs: attempting to describe one changes its behavior.]