How did "Today's Puzzler" float to the top?

The header for the thread says that there was a “Last comment: 03/13/2011 06:30:49 AM”, which I can’t find. I started to post this question within the thread and then realized I’d destroy the evidence.

Spam was deleted.

Thanks. Does that mean someone who monitors the site decided to delete the comment, or someone deleted their own comment, or would you know? You must also be saying that the code for listing “Last comment:” isn’t smart enough to keep track.

I just saw another thread where you answered this question, and that there were several topics similarly affected.

Sorry to add to the mess!