Whenever the "favorites" tab on my user profile turns blue, indicating that something's changed, I flip over to it to see what's been updated. I sort my favorites by "recent", and my understanding is that the most recently changed questions should float to the top. However, even though my favorites page shows recent activity, I often can not find anything in the question that has changed at all.
Here's an example from today. When I sort my favorites page by "recent", I see this as the top question:
According to this, the question was updated 13 hours ago, by a user named "I could't use snoop". 13 hours ago would be approximately midnight EDT, September 8, 2011. So, where's the update? When I visit the question page and look for the update, I don't see anything from this year, let alone the last 13 hours.
Here's a screenshot of what that page looked like when I asked this question, in case it changes. I looked at all comments, answers, and the question itself. I looked at the edit history. I don't see anything new at all! And this happens a lot. This question is just the most recent example. Can anyone explain this? Is it a bug?