I was looking at an old news item that was on HN, and it was pushed way back. When I did get to the article (the item was in the 14 hundreds..), I noticed that the # of comments is displayed incorrectly - the number of comments is missing completely.
https://img.skitch.com/20101221-b5rea4wjxxkgqpyp2mst3ekswc.jpg
That question does have a bunch of comments..
https://img.skitch.com/20101221-8m4b9ffd8a9kuyjaaw8jnaiy1y.jpg
I am suspecting that the count function that counts the comments is slow in responding? Could this happen because the DB is taking too long to get the results back? Note that I did not find the counts to be incorrect - it just does not show up.